Question:
Who was the head of state of Taiwan in Jun, 2015?

Context:
 Ma Ying-jeou is the head of the state of Taiwan from May, 2008 to May, 2016. 
 Zhang Zuolin is the head of the state of Taiwan from Jun, 1927 to Jun, 1928. 
 Tsai Ing-wen is the head of the state of Taiwan from May, 2016 to Dec, 2022. 
 Du Xigui is the head of the state of Taiwan from Jun, 1926 to Oct, 1926. 
 Yan Xishan is the head of the state of Taiwan from Jan, 1949 to Mar, 1950. 
 Sun Yat-sen is the head of the state of Taiwan from Jan, 1912 to Mar, 1912. 
 Duan Qirui is the head of the state of Taiwan from Nov, 1924 to Apr, 1926. 
 Tan Yankai is the head of the state of Taiwan from Feb, 1928 to Oct, 1928. 
 Yen Chia-kan is the head of the state of Taiwan from Apr, 1975 to May, 1978. 
 Hu Weide is the head of the state of Taiwan from Apr, 1926 to May, 1926. 
 Chiang Kai-shek is the head of the state of Taiwan from Oct, 1928 to Dec, 1931. 
 Wellington Koo is the head of the state of Taiwan from Oct, 1926 to Jun, 1927. 
 Zhou Ziqi is the head of the state of Taiwan from Jun, 1922 to Jun, 1922. 
 Yan Huiqing is the head of the state of Taiwan from May, 1926 to Jun, 1926. 
 Chiang Ching-kuo is the head of the state of Taiwan from May, 1978 to Jan, 1988. 
 Li Zongren is the head of the state of Taiwan from Jan, 1949 to Mar, 1950. 
 Lee Teng-hui is the head of the state of Taiwan from Jan, 1988 to May, 2000. 
 Chen Shui-bian is the head of the state of Taiwan from May, 2000 to May, 2008. 
 Yuan Shikai is the head of the state of Taiwan from Mar, 1912 to Jun, 1916.

Answer:
Question:
Who was the head of state of Taiwan in Jun, 2015?

Context:
 Ma Ying-jeou is the head of the state of Taiwan from May, 2008 to May, 2016. 
 Zhang Zuolin is the head of the state of Taiwan from Jun, 1927 to Jun, 1928. 
 Tsai Ing-wen is the head of the state of Taiwan from May, 2016 to Dec, 2022. 
 Du Xigui is the head of the state of Taiwan from Jun, 1926 to Oct, 1926. 
 Yan Xishan is the head of the state of Taiwan from Jan, 1949 to Mar, 1950. 
 Sun Yat-sen is the head of the state of Taiwan from Jan, 1912 to Mar, 1912. 
 Duan Qirui is the head of the state of Taiwan from Nov, 1924 to Apr, 1926. 
 Tan Yankai is the head of the state of Taiwan from Feb, 1928 to Oct, 1928. 
 Yen Chia-kan is the head of the state of Taiwan from Apr, 1975 to May, 1978. 
 Hu Weide is the head of the state of Taiwan from Apr, 1926 to May, 1926. 
 Chiang Kai-shek is the head of the state of Taiwan from Oct, 1928 to Dec, 1931. 
 Wellington Koo is the head of the state of Taiwan from Oct, 1926 to Jun, 1927. 
 Zhou Ziqi is the head of the state of Taiwan from Jun, 1922 to Jun, 1922. 
 Yan Huiqing is the head of the state of Taiwan from May, 1926 to Jun, 1926. 
 Chiang Ching-kuo is the head of the state of Taiwan from May, 1978 to Jan, 1988. 
 Li Zongren is the head of the state of Taiwan from Jan, 1949 to Mar, 1950. 
 Lee Teng-hui is the head of the state of Taiwan from Jan, 1988 to May, 2000. 
 Chen Shui-bian is the head of the state of Taiwan from May, 2000 to May, 2008. 
 Yuan Shikai is the head of the state of Taiwan from Mar, 1912 to Jun, 1916.

Answer:
user
Ma Ying-jeou
assistant
Question:
Who was the head of state of Taiwan in Jun, 2015?

Context:
 Ma Ying-jeou is the head of the state of Taiwan from May, 2008 to May, 2016. 
 Zhang Zuolin is the head of the state of Taiwan from Jun, 1927 to Jun, 1928. 
 Tsai Ing-wen is the head of the state of Taiwan from May, 2016 to Dec, 2022. 
 Du Xigui is the head of the state of Taiwan from Jun, 1926 to Oct, 1926. 
 Yan Xishan is the head of the state of Taiwan from Jan, 1949 to Mar, 1950. 
 Sun Yat-sen is the head of the state of Taiwan from Jan, 1912 to Mar, 1912. 
 Duan Qirui is the head of the state of Taiwan from Nov, 1924 to Apr, 1926. 
 Tan Yankai is the head of the state of Taiwan from Feb, 1928 to Oct, 1928. 
 Yen Chia-kan is the head of the state of Taiwan from Apr, 1975 to May, 1978. 
 Hu Weide is the head of the state of Taiwan from Apr, 1926 to May, 1926. 
 Chiang Kai-shek is the head of the state of Taiwan from Oct, 1928 to Dec, 1931. 
 Wellington Koo is the head of the state of Taiwan from Oct, 1926 to Jun, 1927. 
 Zhou Ziqi is the head of the state of Taiwan from Jun, 1922 to Jun, 1922. 
 Yan Huiqing is the head of the state of Taiwan from May, 1926 to Jun, 1926. 
 Chiang Ching-kuo is the head of the state of Taiwan from May, 1978 to Jan, 1988. 
 Li Zongren is the head of the state of Taiwan from Jan, 1949 to Mar, 1950. 
 Lee Teng-hui is the head of the state of Taiwan from Jan, 1988 to May, 2000. 
 Chen Shui-bian is the head of the state of Taiwan from May, 2000 to May, 2008. 
 Yuan Shikai is the head of the state of Taiwan from Mar, 1912 to Jun, 1916.

Answer:
user
Chiang Ching-kuo
Tan Yankai
Yuan Shikai
Zhou Ziqi
Hu Weide
Sun Yat-sen
Lee Teng-hui
Duan Qirui
Yan Xishan
Yan Huiqing
Chen Shui-bian
Du Xigui
Wellington Koo
Li Zongren
Yen Chia-kan
Zhang Zuolin
Tsai Ing-wen
Chiang Kai-shek
assistant
Question:
Who was the head of state of Taiwan in Jun, 2015?

Context:
 Ma Ying-jeou is the head of the state of Taiwan from May, 2008 to May, 2016. 
 Zhang Zuolin is the head of the state of Taiwan from Jun, 1927 to Jun, 1928. 
 Tsai Ing-wen is the head of the state of Taiwan from May, 2016 to Dec, 2022. 
 Du Xigui is the head of the state of Taiwan from Jun, 1926 to Oct, 1926. 
 Yan Xishan is the head of the state of Taiwan from Jan, 1949 to Mar, 1950. 
 Sun Yat-sen is the head of the state of Taiwan from Jan, 1912 to Mar, 1912. 
 Duan Qirui is the head of the state of Taiwan from Nov, 1924 to Apr, 1926. 
 Tan Yankai is the head of the state of Taiwan from Feb, 1928 to Oct, 1928. 
 Yen Chia-kan is the head of the state of Taiwan from Apr, 1975 to May, 1978. 
 Hu Weide is the head of the state of Taiwan from Apr, 1926 to May, 1926. 
 Chiang Kai-shek is the head of the state of Taiwan from Oct, 1928 to Dec, 1931. 
 Wellington Koo is the head of the state of Taiwan from Oct, 1926 to Jun, 1927. 
 Zhou Ziqi is the head of the state of Taiwan from Jun, 1922 to Jun, 1922. 
 Yan Huiqing is the head of the state of Taiwan from May, 1926 to Jun, 1926. 
 Chiang Ching-kuo is the head of the state of Taiwan from May, 1978 to Jan, 1988. 
 Li Zongren is the head of the state of Taiwan from Jan, 1949 to Mar, 1950. 
 Lee Teng-hui is the head of the state of Taiwan from Jan, 1988 to May, 2000. 
 Chen Shui-bian is the head of the state of Taiwan from May, 2000 to May, 2008. 
 Yuan Shikai is the head of the state of Taiwan from Mar, 1912 to Jun, 1916.

Answer:
user
Ma Ying-jeou
assistant