foo.cc: In function ‘int main()’:
foo.cc:25:27: warning: ‘k’ may be used uninitialized [-Wmaybe-uninitialized]
   25 |         for (int i = k; i > 0; i--)
      |                         ~~^~~
foo.cc:13:21: note: ‘k’ was declared here
   13 |         int cnt = 0,k;
      |                     ^