Petya loves lucky numbers. We all know that lucky numbers are the positive integers whose decimal representations contain only the lucky digits 4 and 7. For example, numbers 47, 744, 4 are lucky and 5, 17, 467 are not.

Unfortunately, not all numbers are lucky. Petya calls a number nearly lucky if the number of lucky digits in it is a lucky number. He wonders whether number n is a nearly lucky number.

Input

The only line contains an integer n (1 ≤ n ≤ 1018).

Please do not use the %lld specificator to read or write 64-bit numbers in С++. It is preferred to use the cin, cout streams or the %I64d specificator.

Output

Print on the single line "YES" if n is a nearly lucky number. Otherwise, print "NO" (without the quotes).

Examples

Input

40047


Output

NO


Input

7747774


Output

YES


Input

1000000000000000000


Output

NO

Note

In the first sample there are 3 lucky digits (first one and last two), so the answer is "NO".

In the second sample there are 7 lucky digits, 7 is lucky number, so the answer is "YES".

In the third sample there are no lucky digits, so the answer is "NO".
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.FileReader; 
import java.io.FileWriter;
//import java.lang.StringBuilder;
//import java.util.StringTokenizer;
//import java.lang.Comparable;
//import java.util.Arrays;
//import java.util.HashMap;
//import java.util.ArrayList;
//import java.util.LinkedList;

public class NearlyLuckyNumber {
    
    static BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    static PrintWriter out = new PrintWriter(System.out);
    //static StringBuilder sb = new StringBuilder();
    
    public static void main(String[] args) throws IOException {
        //BufferedReader in = new BufferedReader(new FileReader("input.txt"));
        //PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("output.txt")));
        //int n = Integer.parseInt(in.readLine());
        //StringTokenizer st = new StringTokenizer(in.readLine());
        //StringTokenizer st = new StringTokenizer(in.readLine());
        //StringTokenizer st = new StringTokenizer(in.readLine());
        char[] c1 = in.readLine().toCharArray();
        int n = 0;
        for(int i = 0; i < c1.length; i++) {
            if(c1[i] == '7' || c1[i] == '4') {
                n++;
            }
        }
        char[] c = (n+"").toCharArray();
        for(int i = 0; i < c.length; i++) {
            if(c[i] != '7' && c[i] != '4') {
                out.print("NO");
                out.close();
                return;
            }
        }
        out.print("YES");
        out.close();
    }
}