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.math.BigInteger;
import java.util.*;
import java.io.*;

public class Practice {

    static void print(Object a) {
        System.out.print(a);
    }

    static void println(Object a) {
        System.out.println(a);
    }

    public static void main (String [] args) {
        FastIO in = new FastIO(System.in);

        long a = in.nextLong();
        String conv = String.valueOf(a);
        //count number of lucky digits
        int count = 0;
        for (int i = 0; i < conv.length(); i++) {
            if (conv.charAt(i) == '4' || conv.charAt(i) == '7')
                count++;
        }

        if (isLucky(count))
            println("YES");
        else
            println("NO");

    }

    public static boolean isLucky(long n) {
        String conv = String.valueOf(n);
        for (int i = 0; i < conv.length(); i++) {
            if (conv.charAt(i) != '4' && conv.charAt(i) != '7')
                return false;
        }
        return true;
    }

}

class FastIO {

    BufferedReader br;
    StringTokenizer st;

    public FastIO (InputStream is) {
        br = new BufferedReader(new InputStreamReader(is));
    }

    String next () {
        while (st == null || !st.hasMoreElements()) {
            try {
                st = new StringTokenizer(br.readLine());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return st.nextToken();
    }
    int nextInt () {
        return Integer.parseInt(next());
    }
    long nextLong () {
        return Long.parseLong(next());
    }
    double nextDouble () {
        return Double.parseDouble(next());
    }
    float nextFloat () {
        return Float.parseFloat(next());
    }
}
