prog.cpp:1:12: error: variable or field 'gamma' declared void
void gamma(string s1, string s2, string &res)
^
prog.cpp:1:12: error: 'string' was not declared in this scope
prog.cpp:1:23: error: 'string' was not declared in this scope
void gamma(string s1, string s2, string &res)
^
prog.cpp:1:34: error: 'string' was not declared in this scope
void gamma(string s1, string s2, string &res)
^
prog.cpp:1:42: error: 'res' was not declared in this scope
void gamma(string s1, string s2, string &res)
^