foo.cc: In function ‘int main()’:
foo.cc:17:9: warning: this ‘else’ clause does not guard... [-Wmisleading-indentation]
   17 |         else
      |         ^~~~
foo.cc:19:17: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the ‘else’
   19 |                 sum=0;
      |                 ^~~