/in/foo.cc: In function 'int main()':
/in/foo.cc:7:15: warning: left operand of comma operator has no effect [-Wunused-value]
  for(int i=1;i<=n/2,i<=9;i++){
              ~^~~~~
/in/foo.cc:8:3: error: 'ans' was not declared in this scope
   ans++;
   ^~~
/in/foo.cc:19:8: error: 'ans' was not declared in this scope
  cout<<ans;
        ^~~