/in/foo.cc: In function 'int main()':
/in/foo.cc:14:11: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   if (b%2 && b%10!=1 || b<a)
       ~~~~^~~~~~~~~~
/in/foo.cc:39:29: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::stack<long long int>::size_type {aka long unsigned int}' [-Wformat=]
  printf("YES\n%d\n",s.size());
                             ^