foo.cc: In function ‘int main()’:
foo.cc:6:17: warning: ‘m’ is used uninitialized [-Wuninitialized]
    6 |         for(int i=m;i<=n;i++){
      |                 ^
foo.cc:5:13: note: ‘m’ was declared here
    5 |         int m,n,y,x=0;
      |             ^
foo.cc:6:22: warning: ‘n’ is used uninitialized [-Wuninitialized]
    6 |         for(int i=m;i<=n;i++){
      |                     ~^~~
foo.cc:5:15: note: ‘n’ was declared here
    5 |         int m,n,y,x=0;
      |               ^