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".
# File: Nearly Lucky
# Problem: http://codeforces.com/contest/110/problem/A


import sys

def isLuckyNumber(n):

	flag = True
	if n < 4:
		return False

	#loop through digits of number, and break if digit not 4 or 7
	while (n > 1):
		
		current_digit = n%10
	        

		if (current_digit != 4) and (current_digit != 7):
			return False
			break
		n = int(n/10)

	return True


def isNearlyLucky(num):
	#input_num is nearly lucky if the number of digits in it is a lucky number
	
	lucky_count = 0
	for digit in str(num):
		if (digit == '4') or (digit == '7'):
			lucky_count += 1

	return isLuckyNumber(lucky_count)



n = raw_input()

if isNearlyLucky(n) == True:
	print "YES"
else:
	print "NO"
