/in/foo.cc: In function 'int change(long long int)':
/in/foo.cc:21:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:27:24: error: expected ';' before '{' token
  if (a>b) change (a-b) {
                        ^
/in/foo.cc:25:16: warning: unused variable 'c' [-Wunused-variable]
  long long a,b,c;
                ^