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 math

def BearAndBigBrother():
    a, b = map(int, input().split(' '))
    year = 0
    while 1:
        if a > b:
            break
        else:
            a *= 3
            b *= 2
            year += 1
    print(year)
    return None

def Tram():
    n = int(input())
    p = [0]
    for i in range(1, n+1):
        a, b = map(int, input().split())
        tmp = p[i-1]
        tmp -= a
        tmp += b
        p.append(tmp)
    print(max(p))
    return None


def WrongSubtraction():
    n ,k = map(int, input().split())
    for i in range(k):
        if n % 10 == 0:
            n = n // 10
        else:
            n -= 1
    print(n)
    return None


def Elephant():
    x = int(input())
    i = steps = 0
    tmp = [j for j in range(1, 6) if x // j > 0]
    stepsize = max(tmp)
    while i < x:
        steps += (x-i) // stepsize
        i += stepsize*steps
        tmp2 = [j for j in range(1, stepsize) if (x-i) // j > 0]
        try:
            stepsize = max(tmp2)
        except:
            continue
    print(steps)

    return None


def QueueAtTheSchool():
    n, t = map(int, input().split())
    s = input()
    Q = [i for i in s]
    for i in range(t):
        j = 0
        while j < len(Q)-1:
            if Q[j] == 'B' and Q[j+1] == 'G':
                Q[j], Q[j+1] = Q[j+1], Q[j]
                j += 2
            else:
                j += 1
    s_f = ''.join(Q)
    print(s_f)

    return None
'''

def NearlyLuckyNumber():
    n = input()
    nl = str(n.count('4') + n.count('7'))
    tmp = set([i for i in nl])
    if (len(tmp) <= 2) and (('4' in tmp) or ('7' in tmp)):
        print('YES')
    else:
        print('NO')
    

def main():
    #BearAndBigBrother()
    #Tram()
    #WrongSubtraction()
    #Elephant()
    #QueueAtTheSchool()
    NearlyLuckyNumber()

main()
