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".
#-*-coding:utf-8-*-

import string
import sys
reload(sys)
sys.setdefaultencoding('utf-8')

# n (1 ≤ n ≤ 10^18).

# 4,7은 행운의 숫자
# nearly lucky = 4 혹은 7의 개수가 4 혹은 7로 이루어져야함
# 40047 : 4의개수 + 7의 개수  = 3 != 4 or 7
# 7747774 : 4의개수 + 7의 개수 = 7 = 4 or 7


num = raw_input()



count = 0
for i in range(len(num)) :
	if num[i] == '4' or num[i] == '7' : count = count +1


if count == 4 or count == 7 : print 'YES'
else 						: print 'NO' 