Problem:
Score : 100 points

Problem Statement

You are given four digits N_1, N_2, N_3 and N_4. Determine if these can be arranged into the sequence of digits "1974".

Constraints

0 \leq N_1, N_2, N_3, N_4 \leq 9

N_1, N_2, N_3 and N_4 are integers.

Input

Input is given from Standard Input in the following format:

N_1 N_2 N_3 N_4

Output

If N_1, N_2, N_3 and N_4 can be arranged into the sequence of digits "1974", print YES; if they cannot, print NO.

Sample Input 1

1 7 9 4

Sample Output 1

YES

We can get 1974 by swapping N_2 and N_3.

Sample Input 2

1 9 7 4

Sample Output 2

YES

We already have 1974 before doing anything.

Sample Input 3

1 2 9 1

Sample Output 3

NO

Sample Input 4

4 9 0 8

Sample Output 4

NO

Solution in C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
#define INF LLONG_MAX
#define ll  long long
#define ull unsigned long long
#define rep(i,n) for(int i=0; i<n; ++i)
#define MOD 1000000007
using namespace std;
template<class T> inline bool chmin(T& a, T b) { if(a>b) {a=b; return true;} return false;}
template<class T> inline bool chmax(T& a, T b) { if(a<b) {a=b; return true;} return false;}

int main() {
  vector<int> N(4); rep(i,4) cin >> N[i];
  vector<bool> mem(4, false);
  for(int i:N) {
    if(i==1) mem[0] = true;
    else if(i==9) mem[1] = true;
    else if(i==4) mem[2] = true;
    else if(i==7) mem[3] = true;
  }
  bool flg = true;
  for(bool b:mem) {
    if(!b) flg = false;
  }
  printf(flg?"YES":"NO");
}