Question:
Who was the head of Berlin in Sep, 1957?

Context:
 Klaus Wowereit is the head of the government of Berlin from Jun, 2001 to Dec, 2014. 
 Franziska Giffey is the head of the government of Berlin from Dec, 2021 to Dec, 2022. 
 Walther Schreiber is the head of the government of Berlin from Oct, 1953 to Jan, 1955. 
 Willy Brandt is the head of the government of Berlin from Oct, 1957 to Dec, 1966. 
 Walter Momper is the head of the government of Berlin from Mar, 1989 to Jan, 1991. 
 Ernst Reuter is the head of the government of Berlin from Dec, 1948 to Oct, 1953. 
 Dietrich Stobbe is the head of the government of Berlin from May, 1977 to Jan, 1981. 
 Klaus Schütz is the head of the government of Berlin from Oct, 1967 to May, 1977. 
 Eberhard Diepgen is the head of the government of Berlin from Jan, 1991 to Jun, 2001. 
 Hans-Jochen Vogel is the head of the government of Berlin from Jan, 1981 to Jun, 1981. 
 Franz Amrehn is the head of the government of Berlin from Aug, 1957 to Oct, 1957. 
 Heinrich Albertz is the head of the government of Berlin from Dec, 1966 to Oct, 1967. 
 Richard von Weizsäcker is the head of the government of Berlin from Jun, 1981 to Feb, 1984. 
 Otto Suhr is the head of the government of Berlin from Jan, 1955 to Aug, 1957. 
 Michael Müller is the head of the government of Berlin from Dec, 2014 to Dec, 2021.

Answer:
Question:
Who was the head of Berlin in Sep, 1957?

Context:
 Klaus Wowereit is the head of the government of Berlin from Jun, 2001 to Dec, 2014. 
 Franziska Giffey is the head of the government of Berlin from Dec, 2021 to Dec, 2022. 
 Walther Schreiber is the head of the government of Berlin from Oct, 1953 to Jan, 1955. 
 Willy Brandt is the head of the government of Berlin from Oct, 1957 to Dec, 1966. 
 Walter Momper is the head of the government of Berlin from Mar, 1989 to Jan, 1991. 
 Ernst Reuter is the head of the government of Berlin from Dec, 1948 to Oct, 1953. 
 Dietrich Stobbe is the head of the government of Berlin from May, 1977 to Jan, 1981. 
 Klaus Schütz is the head of the government of Berlin from Oct, 1967 to May, 1977. 
 Eberhard Diepgen is the head of the government of Berlin from Jan, 1991 to Jun, 2001. 
 Hans-Jochen Vogel is the head of the government of Berlin from Jan, 1981 to Jun, 1981. 
 Franz Amrehn is the head of the government of Berlin from Aug, 1957 to Oct, 1957. 
 Heinrich Albertz is the head of the government of Berlin from Dec, 1966 to Oct, 1967. 
 Richard von Weizsäcker is the head of the government of Berlin from Jun, 1981 to Feb, 1984. 
 Otto Suhr is the head of the government of Berlin from Jan, 1955 to Aug, 1957. 
 Michael Müller is the head of the government of Berlin from Dec, 2014 to Dec, 2021.

Answer:
user
Franz Amrehn
assistant
Question:
Who was the head of Berlin in Sep, 1957?

Context:
 Klaus Wowereit is the head of the government of Berlin from Jun, 2001 to Dec, 2014. 
 Franziska Giffey is the head of the government of Berlin from Dec, 2021 to Dec, 2022. 
 Walther Schreiber is the head of the government of Berlin from Oct, 1953 to Jan, 1955. 
 Willy Brandt is the head of the government of Berlin from Oct, 1957 to Dec, 1966. 
 Walter Momper is the head of the government of Berlin from Mar, 1989 to Jan, 1991. 
 Ernst Reuter is the head of the government of Berlin from Dec, 1948 to Oct, 1953. 
 Dietrich Stobbe is the head of the government of Berlin from May, 1977 to Jan, 1981. 
 Klaus Schütz is the head of the government of Berlin from Oct, 1967 to May, 1977. 
 Eberhard Diepgen is the head of the government of Berlin from Jan, 1991 to Jun, 2001. 
 Hans-Jochen Vogel is the head of the government of Berlin from Jan, 1981 to Jun, 1981. 
 Franz Amrehn is the head of the government of Berlin from Aug, 1957 to Oct, 1957. 
 Heinrich Albertz is the head of the government of Berlin from Dec, 1966 to Oct, 1967. 
 Richard von Weizsäcker is the head of the government of Berlin from Jun, 1981 to Feb, 1984. 
 Otto Suhr is the head of the government of Berlin from Jan, 1955 to Aug, 1957. 
 Michael Müller is the head of the government of Berlin from Dec, 2014 to Dec, 2021.

Answer:
user
Eberhard Diepgen
Hans-Jochen Vogel
Otto Suhr
Klaus Schütz
Richard von Weizsäcker
Willy Brandt
Walter Momper
Franziska Giffey
Klaus Wowereit
Michael Müller
Ernst Reuter
Walther Schreiber
Dietrich Stobbe
Heinrich Albertz
assistant
Question:
Who was the head of Berlin in Sep, 1957?

Context:
 Klaus Wowereit is the head of the government of Berlin from Jun, 2001 to Dec, 2014. 
 Franziska Giffey is the head of the government of Berlin from Dec, 2021 to Dec, 2022. 
 Walther Schreiber is the head of the government of Berlin from Oct, 1953 to Jan, 1955. 
 Willy Brandt is the head of the government of Berlin from Oct, 1957 to Dec, 1966. 
 Walter Momper is the head of the government of Berlin from Mar, 1989 to Jan, 1991. 
 Ernst Reuter is the head of the government of Berlin from Dec, 1948 to Oct, 1953. 
 Dietrich Stobbe is the head of the government of Berlin from May, 1977 to Jan, 1981. 
 Klaus Schütz is the head of the government of Berlin from Oct, 1967 to May, 1977. 
 Eberhard Diepgen is the head of the government of Berlin from Jan, 1991 to Jun, 2001. 
 Hans-Jochen Vogel is the head of the government of Berlin from Jan, 1981 to Jun, 1981. 
 Franz Amrehn is the head of the government of Berlin from Aug, 1957 to Oct, 1957. 
 Heinrich Albertz is the head of the government of Berlin from Dec, 1966 to Oct, 1967. 
 Richard von Weizsäcker is the head of the government of Berlin from Jun, 1981 to Feb, 1984. 
 Otto Suhr is the head of the government of Berlin from Jan, 1955 to Aug, 1957. 
 Michael Müller is the head of the government of Berlin from Dec, 2014 to Dec, 2021.

Answer:
user
Franz Amrehn
assistant