/in/foo.cc: In function 'int main()':
/in/foo.cc:19:8: warning: 'cnt' may be used uninitialized in this function [-Wmaybe-uninitialized]
  cout<<cnt<<endl<<s;
        ^~~
/in/foo.cc:19:20: warning: 's' may be used uninitialized in this function [-Wmaybe-uninitialized]
  cout<<cnt<<endl<<s;
                    ^