/in/foo.cc: In function 'int main()':
/in/foo.cc:9:15: error: 'cnt' was not declared in this scope
    if(c=='1') cnt++;
               ^~~
/in/foo.cc:11:15: error: 'cnt' was not declared in this scope
    if(c=='1') cnt++;
               ^~~
/in/foo.cc:13:15: error: 'cnt' was not declared in this scope
    if(c=='1') cnt++;
               ^~~
/in/foo.cc:15:15: error: 'cnt' was not declared in this scope
    if(c=='1') cnt++;
               ^~~
/in/foo.cc:17:15: error: 'cnt' was not declared in this scope
    if(c=='1') cnt++;
               ^~~
/in/foo.cc:19:15: error: 'cnt' was not declared in this scope
    if(c=='1') cnt++;
               ^~~
/in/foo.cc:21:15: error: 'cnt' was not declared in this scope
    if(c=='1') cnt++;
               ^~~
/in/foo.cc:23:15: error: 'cnt' was not declared in this scope
    if(c=='1') cnt++;
               ^~~
/in/foo.cc:26:10: error: 'cnt' was not declared in this scope
    cout<<cnt<<endl;
          ^~~