/in/foo.cc:5:11: error: '::main' must return 'int'
 void main(){
           ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:8:12: warning: overflow in implicit constant conversion [-Woverflow]
  int limit=16679880978201;
            ^~~~~~~~~~~~~~
/in/foo.cc:8:6: warning: unused variable 'limit' [-Wunused-variable]
  int limit=16679880978201;
      ^~~~~