#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using Graph=vector<vector<int>>;
#define INF 1000000000

int main(){
  string S;
  cin>>S;
  if(S[0]=='4'||S[0]=='t'){
    cout<<"Yes"<<'\n';
  }else{
    cout<<"No"<<'\n';
  }
}