foo.cc: In function ‘int gbs(int, int)’:
foo.cc:10:16: warning: ‘res’ may be used uninitialized [-Wmaybe-uninitialized]
   10 |         return res;
      |                ^~~
foo.cc:4:19: note: ‘res’ was declared here
    4 |         int small,res;
      |                   ^~~
foo.cc: In function ‘int gys(int, int)’:
foo.cc:20:16: warning: ‘res’ may be used uninitialized [-Wmaybe-uninitialized]
   20 |         return res;
      |                ^~~
foo.cc:14:17: note: ‘res’ was declared here
   14 |         int big,res;
      |                 ^~~
foo.cc: In function ‘int main()’:
foo.cc:28:20: warning: ‘res’ may be used uninitialized [-Wmaybe-uninitialized]
   28 |         cout<<Gbs<<" "<<Gys<<endl;
      |                    ^~~
foo.cc:4:19: note: ‘res’ was declared here
    4 |         int small,res;
      |                   ^~~