#include <iostream>
#include <string>
int main()
{
std::cout << "welcome. code please? " ;
std::string x ; // we want to read in a string
std::cin >> x;
// note: use double quotes " for string, single quotes ' for char
if( x == "*121#" ) std::cout << "congrats\n" ;
else std::cout << "invalid\n";
}