foo.cc: In function ‘int gbs(int, int)’:
foo.cc:11:16: warning: ‘res’ may be used uninitialized [-Wmaybe-uninitialized]
   11 |         return res;
      |                ^~~
foo.cc:5:19: note: ‘res’ was declared here
    5 |         int small,res;
      |                   ^~~
foo.cc: In function ‘int gys(int, int)’:
foo.cc:21:16: warning: ‘res’ may be used uninitialized [-Wmaybe-uninitialized]
   21 |         return res;
      |                ^~~
foo.cc:15:17: note: ‘res’ was declared here
   15 |         int big,res;
      |                 ^~~
foo.cc: In function ‘int main()’:
foo.cc:29:20: warning: ‘res’ may be used uninitialized [-Wmaybe-uninitialized]
   29 |         cout<<Gbs<<" "<<Gys<<endl;
      |                    ^~~
foo.cc:5:19: note: ‘res’ was declared here
    5 |         int small,res;
      |                   ^~~