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.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
 
public class Solution {
    public static void main(String[] args) throws IOException {
        FastScanner fs = new FastScanner();
        String str = fs.br.readLine();
 
        solve(str);
    }
 
    public static void solve(String str) {
        boolean lucky = true;
        int count = 0;
        for (int i = 0; i < str.length(); i++) {
            char c = str.charAt(i);
            if (c == '4' || c == '7') {
                count++;
            }
        }


        if (count == 0) lucky = false;

        while(count > 0 && lucky) {
            int last = count % 10;
            count /= 10;

            if (last != 4 && last != 7) {
                lucky = false;
                break;
            }
        }
 
        if (lucky) {
            System.out.println("YES");
        } else {
            System.out.println("NO");
        }
    }
 
    static class FastScanner {
        // br.readLine(), for whole line
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st = new StringTokenizer("");
 
		String next() {
 
			while (!st.hasMoreTokens()) {
				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());
		}
	}
}