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.*;
import java.util.*;
import java.math.*;
import java.awt.*;

public class A {

	MyScanner in;
	PrintWriter out;

	public static void main(String[] args) throws Exception {
		new A().run();
	}

	public void run() throws Exception {
		in = new MyScanner();
		out = new PrintWriter(System.out);

		solve();

		out.close();
	}

	public void solve() throws Exception {
		long n = in.nextLong();
		int k = 0;
		while (n > 0) {
			if ((n % 10 == 4) || (n % 10 == 7)) {
				k++;
			}
			n /= 10;
		}
		boolean lucky = (k > 0);
		while (k > 0) {
			if ((k % 10 != 4) && (k % 10 != 7)) {
				lucky = false;
			}
			k /= 10;
		}
		out.println(lucky ? "YES" : "NO");
	}

	class MyScanner {
		BufferedReader br;
		StringTokenizer st;

		public MyScanner() throws Exception {
			br = new BufferedReader(new InputStreamReader(System.in));
		}

		String next() throws Exception {
			while ((st == null) || (!st.hasMoreTokens())) {
				st = new StringTokenizer(br.readLine());
			}
			return st.nextToken();
		}

		int nextInt() throws Exception {
			return Integer.parseInt(next());
		}

		double nextDouble() throws Exception {
			return Double.parseDouble(next());
		}

		boolean nextBoolean() throws Exception {
			return Boolean.parseBoolean(next());
		}

		long nextLong() throws Exception {
			return Long.parseLong(next());
		}
	}

}