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".
"""Template for Python Competitive Programmers prepared by Mayank Chaudhary aka chaudhary_19"""

# to use the print and division function of Python3
from __future__ import division, print_function

"""value of mod"""
MOD = 10 ** 9 + 7

"""use resource"""
# import resource
# resource.setrlimit(resource.RLIMIT_STACK, [0x100000000, resource.RLIM_INFINITY])

"""uncomment next 4 lines while doing recursion based question"""
# import threading
# threading.stack_size(2**27)
import sys

# sys.setrecursionlimit(10**6)

"""uncomment next 7 lines while doing nCr question"""
# fact=[1]
# for i in range(1,100001):
#    fact.append((fact[-1]*i)%mod)
# ifact=[0]*100001
# ifact[100000]=pow(fact[100000],mod-2,mod)
# for i in range(100000,0,-1):
#    ifact[i-1]=(i*ifact[i])%mod

"""uncomment modules according to your need"""
# from bisect import bisect_left as bl# c++ lowerbound bl(array,element)
# from bisect import bisect_right as br  # c++ upperbound
# import itertools
# import collections
# import math
# import heapq
# from random import randint as rn
# from Queue import Queue as Q

'''
def modinv(n, p):
    return pow(n, p - 2, p)
'''

'''
def ncr(n, r, p):  # for using this uncomment the lines calculating fact and ifact
    t = ((fact[n]) * ((ifact[r] * ifact[n - r]) % p)) % p
    return t
'''


def get_ints(): return map(int, sys.stdin.readline().strip().split())


def get_array(): return list(map(int, sys.stdin.readline().strip().split()))


def input(): return sys.stdin.readline().strip()


'''
def GCD(x, y):
    while (y):
        x, y = y, x % y
    return x
'''

"""*******************************************************"""


def main():

    string = input()
    count = 0
    for i in string:
        if i=='4' or i=='7':
            count += 1
    if count==4 or count==7:
        print('YES')
    else:
        print('NO')



""" -------- Python 2 and 3 footer by Pajenegod and c1729 ---------"""

py2 = round(0.5)
if py2:
    from future_builtins import ascii, filter, hex, map, oct, zip

    range = xrange

import os, sys
from io import IOBase, BytesIO

BUFSIZE = 8192


class FastIO(BytesIO):
    newlines = 0

    def __init__(self, file):
        self._file = file
        self._fd = file.fileno()
        self.writable = "x" in file.mode or "w" in file.mode
        self.write = super(FastIO, self).write if self.writable else None

    def _fill(self):
        s = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
        self.seek((self.tell(), self.seek(0, 2), super(FastIO, self).write(s))[0])
        return s

    def read(self):
        while self._fill(): pass
        return super(FastIO, self).read()

    def readline(self):
        while self.newlines == 0:
            s = self._fill();
            self.newlines = s.count(b"\n") + (not s)
        self.newlines -= 1
        return super(FastIO, self).readline()

    def flush(self):
        if self.writable:
            os.write(self._fd, self.getvalue())
            self.truncate(0), self.seek(0)


class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        if py2:
            self.write = self.buffer.write
            self.read = self.buffer.read
            self.readline = self.buffer.readline
        else:
            self.write = lambda s: self.buffer.write(s.encode('ascii'))
            self.read = lambda: self.buffer.read().decode('ascii')
            self.readline = lambda: self.buffer.readline().decode('ascii')


sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
input = lambda: sys.stdin.readline().rstrip('\r\n')

""" main function"""

if __name__ == '__main__':
    main()
# threading.Thread(target=main).start()