Question:
Who was the head of state of Denmark in Apr, 1821?

Context:
 Christian VII of Denmark is the head of the state of Denmark from Jan, 1766 to Mar, 1808. 
 Frederick I of Denmark is the head of the state of Denmark from Apr, 1523 to Apr, 1533. 
 Christian I of Denmark is the head of the state of Denmark from Sep, 1448 to May, 1481. 
 Frederick IX of Denmark is the head of the state of Denmark from Apr, 1947 to Jan, 1972. 
 Frederick VI of Denmark is the head of the state of Denmark from Mar, 1808 to Dec, 1839. 
 Christian VI of Denmark is the head of the state of Denmark from Oct, 1730 to Aug, 1746. 
 Frederick VIII of Denmark is the head of the state of Denmark from Jan, 1906 to May, 1912. 
 Christian III of Denmark is the head of the state of Denmark from Jul, 1534 to Jan, 1559. 
 Frederick V of Denmark is the head of the state of Denmark from Aug, 1746 to Jan, 1766. 
 Christian II of Denmark is the head of the state of Denmark from Feb, 1513 to Apr, 1523. 
 Christian V of Denmark is the head of the state of Denmark from Feb, 1670 to Aug, 1699. 
 Frederick III of Denmark is the head of the state of Denmark from Jul, 1648 to Feb, 1670. 
 Christian IX of Denmark is the head of the state of Denmark from Nov, 1863 to Jan, 1906. 
 Frederick VII of Denmark is the head of the state of Denmark from Jan, 1848 to Nov, 1863. 
 Frederick II of Denmark is the head of the state of Denmark from Jan, 1559 to Apr, 1588. 
 Margrethe II of Denmark is the head of the state of Denmark from Jan, 1972 to Jan, 1972. 
 Eric of Pomerania is the head of the state of Denmark from Jan, 1396 to Jan, 1439. 
 John, King of Denmark is the head of the state of Denmark from May, 1481 to Feb, 1513. 
 Frederick IV of Denmark is the head of the state of Denmark from Aug, 1699 to Oct, 1730. 
 Christian X of Denmark is the head of the state of Denmark from May, 1912 to Apr, 1947. 
 Christian VIII of Denmark is the head of the state of Denmark from Dec, 1839 to Jan, 1848. 
 Christian IV of Denmark is the head of the state of Denmark from Apr, 1588 to Feb, 1648. 
 Christopher of Bavaria is the head of the state of Denmark from Apr, 1440 to Jan, 1448.

Answer:
Question:
Who was the head of state of Denmark in Apr, 1821?

Context:
 Christian VII of Denmark is the head of the state of Denmark from Jan, 1766 to Mar, 1808. 
 Frederick I of Denmark is the head of the state of Denmark from Apr, 1523 to Apr, 1533. 
 Christian I of Denmark is the head of the state of Denmark from Sep, 1448 to May, 1481. 
 Frederick IX of Denmark is the head of the state of Denmark from Apr, 1947 to Jan, 1972. 
 Frederick VI of Denmark is the head of the state of Denmark from Mar, 1808 to Dec, 1839. 
 Christian VI of Denmark is the head of the state of Denmark from Oct, 1730 to Aug, 1746. 
 Frederick VIII of Denmark is the head of the state of Denmark from Jan, 1906 to May, 1912. 
 Christian III of Denmark is the head of the state of Denmark from Jul, 1534 to Jan, 1559. 
 Frederick V of Denmark is the head of the state of Denmark from Aug, 1746 to Jan, 1766. 
 Christian II of Denmark is the head of the state of Denmark from Feb, 1513 to Apr, 1523. 
 Christian V of Denmark is the head of the state of Denmark from Feb, 1670 to Aug, 1699. 
 Frederick III of Denmark is the head of the state of Denmark from Jul, 1648 to Feb, 1670. 
 Christian IX of Denmark is the head of the state of Denmark from Nov, 1863 to Jan, 1906. 
 Frederick VII of Denmark is the head of the state of Denmark from Jan, 1848 to Nov, 1863. 
 Frederick II of Denmark is the head of the state of Denmark from Jan, 1559 to Apr, 1588. 
 Margrethe II of Denmark is the head of the state of Denmark from Jan, 1972 to Jan, 1972. 
 Eric of Pomerania is the head of the state of Denmark from Jan, 1396 to Jan, 1439. 
 John, King of Denmark is the head of the state of Denmark from May, 1481 to Feb, 1513. 
 Frederick IV of Denmark is the head of the state of Denmark from Aug, 1699 to Oct, 1730. 
 Christian X of Denmark is the head of the state of Denmark from May, 1912 to Apr, 1947. 
 Christian VIII of Denmark is the head of the state of Denmark from Dec, 1839 to Jan, 1848. 
 Christian IV of Denmark is the head of the state of Denmark from Apr, 1588 to Feb, 1648. 
 Christopher of Bavaria is the head of the state of Denmark from Apr, 1440 to Jan, 1448.

Answer:
user
Frederick VI of Denmark
assistant
Question:
Who was the head of state of Denmark in Apr, 1821?

Context:
 Christian VII of Denmark is the head of the state of Denmark from Jan, 1766 to Mar, 1808. 
 Frederick I of Denmark is the head of the state of Denmark from Apr, 1523 to Apr, 1533. 
 Christian I of Denmark is the head of the state of Denmark from Sep, 1448 to May, 1481. 
 Frederick IX of Denmark is the head of the state of Denmark from Apr, 1947 to Jan, 1972. 
 Frederick VI of Denmark is the head of the state of Denmark from Mar, 1808 to Dec, 1839. 
 Christian VI of Denmark is the head of the state of Denmark from Oct, 1730 to Aug, 1746. 
 Frederick VIII of Denmark is the head of the state of Denmark from Jan, 1906 to May, 1912. 
 Christian III of Denmark is the head of the state of Denmark from Jul, 1534 to Jan, 1559. 
 Frederick V of Denmark is the head of the state of Denmark from Aug, 1746 to Jan, 1766. 
 Christian II of Denmark is the head of the state of Denmark from Feb, 1513 to Apr, 1523. 
 Christian V of Denmark is the head of the state of Denmark from Feb, 1670 to Aug, 1699. 
 Frederick III of Denmark is the head of the state of Denmark from Jul, 1648 to Feb, 1670. 
 Christian IX of Denmark is the head of the state of Denmark from Nov, 1863 to Jan, 1906. 
 Frederick VII of Denmark is the head of the state of Denmark from Jan, 1848 to Nov, 1863. 
 Frederick II of Denmark is the head of the state of Denmark from Jan, 1559 to Apr, 1588. 
 Margrethe II of Denmark is the head of the state of Denmark from Jan, 1972 to Jan, 1972. 
 Eric of Pomerania is the head of the state of Denmark from Jan, 1396 to Jan, 1439. 
 John, King of Denmark is the head of the state of Denmark from May, 1481 to Feb, 1513. 
 Frederick IV of Denmark is the head of the state of Denmark from Aug, 1699 to Oct, 1730. 
 Christian X of Denmark is the head of the state of Denmark from May, 1912 to Apr, 1947. 
 Christian VIII of Denmark is the head of the state of Denmark from Dec, 1839 to Jan, 1848. 
 Christian IV of Denmark is the head of the state of Denmark from Apr, 1588 to Feb, 1648. 
 Christopher of Bavaria is the head of the state of Denmark from Apr, 1440 to Jan, 1448.

Answer:
user
Frederick V of Denmark
Frederick IX of Denmark
Frederick VII of Denmark
Christian VII of Denmark
Frederick II of Denmark
Christian V of Denmark
Christian III of Denmark
Frederick I of Denmark
Christian X of Denmark
Frederick IV of Denmark
Frederick III of Denmark
Frederick VIII of Denmark
Christian II of Denmark
Christopher of Bavaria
Eric of Pomerania
Margrethe II of Denmark
Christian I of Denmark
Christian VI of Denmark
Christian IV of Denmark
John, King of Denmark
Christian VIII of Denmark
Christian IX of Denmark
assistant
Question:
Who was the head of state of Denmark in Apr, 1821?

Context:
 Christian VII of Denmark is the head of the state of Denmark from Jan, 1766 to Mar, 1808. 
 Frederick I of Denmark is the head of the state of Denmark from Apr, 1523 to Apr, 1533. 
 Christian I of Denmark is the head of the state of Denmark from Sep, 1448 to May, 1481. 
 Frederick IX of Denmark is the head of the state of Denmark from Apr, 1947 to Jan, 1972. 
 Frederick VI of Denmark is the head of the state of Denmark from Mar, 1808 to Dec, 1839. 
 Christian VI of Denmark is the head of the state of Denmark from Oct, 1730 to Aug, 1746. 
 Frederick VIII of Denmark is the head of the state of Denmark from Jan, 1906 to May, 1912. 
 Christian III of Denmark is the head of the state of Denmark from Jul, 1534 to Jan, 1559. 
 Frederick V of Denmark is the head of the state of Denmark from Aug, 1746 to Jan, 1766. 
 Christian II of Denmark is the head of the state of Denmark from Feb, 1513 to Apr, 1523. 
 Christian V of Denmark is the head of the state of Denmark from Feb, 1670 to Aug, 1699. 
 Frederick III of Denmark is the head of the state of Denmark from Jul, 1648 to Feb, 1670. 
 Christian IX of Denmark is the head of the state of Denmark from Nov, 1863 to Jan, 1906. 
 Frederick VII of Denmark is the head of the state of Denmark from Jan, 1848 to Nov, 1863. 
 Frederick II of Denmark is the head of the state of Denmark from Jan, 1559 to Apr, 1588. 
 Margrethe II of Denmark is the head of the state of Denmark from Jan, 1972 to Jan, 1972. 
 Eric of Pomerania is the head of the state of Denmark from Jan, 1396 to Jan, 1439. 
 John, King of Denmark is the head of the state of Denmark from May, 1481 to Feb, 1513. 
 Frederick IV of Denmark is the head of the state of Denmark from Aug, 1699 to Oct, 1730. 
 Christian X of Denmark is the head of the state of Denmark from May, 1912 to Apr, 1947. 
 Christian VIII of Denmark is the head of the state of Denmark from Dec, 1839 to Jan, 1848. 
 Christian IV of Denmark is the head of the state of Denmark from Apr, 1588 to Feb, 1648. 
 Christopher of Bavaria is the head of the state of Denmark from Apr, 1440 to Jan, 1448.

Answer:
user
Frederick VI of Denmark
assistant