[알고리즘] 백준 17863 - FYI (C++)

[문제 링크] : https://www.acmicpc.net/problem/17863

#include <iostream>
using namespace std;

string S;

int main(){
    cin >> S;
    if(S.substr(0,3) == "555"){
        cout << "YES\n";
    }
    else{
        cout << "NO\n";
    }
    return 0;
}