/in/foo.cc: In function 'int main()':
/in/foo.cc:20:18: warning: unused variable 'j' [-Wunused-variable]
     int x, y, i, j, num = 0, ans = 1, x1, y1;
                  ^
/in/foo.cc:20:21: warning: unused variable 'num' [-Wunused-variable]
     int x, y, i, j, num = 0, ans = 1, x1, y1;
                     ^~~
/in/foo.cc:20:39: warning: variable 'x1' set but not used [-Wunused-but-set-variable]
     int x, y, i, j, num = 0, ans = 1, x1, y1;
                                       ^~