foo.cc: In function 'int main()':
foo.cc:28:25: error: 'ans' was not declared in this scope; did you mean 'abs'?
   28 |                         ans++;
      |                         ^~~
      |                         abs
foo.cc:34:17: error: 'ans' was not declared in this scope; did you mean 'abs'?
   34 |                 ans++;
      |                 ^~~
      |                 abs
foo.cc:37:15: error: 'ans' was not declared in this scope; did you mean 'abs'?
   37 |         cout<<ans<<endl;
      |               ^~~
      |               abs

[Hydro](https://hydro.ac)提供评测服务