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".
#!/usr/bin/env python
#-*- coding:utf-8 -*-

import sys, math, random, operator
from string import ascii_lowercase, ascii_uppercase
from fractions import Fraction, gcd
#from decimal import Decimal, getcontext
from itertools import product, permutations, combinations
from Queue import Queue, PriorityQueue
from collections import deque, defaultdict, Counter
#getcontext().prec = 100

MOD = 10**9 + 7
INF = float("+inf")

if sys.subversion[0] == "PyPy":
    import io, atexit
    sys.stdout = io.BytesIO()
    atexit.register(lambda: sys.__stdout__.write(sys.stdout.getvalue()))
    sys.stdin = io.BytesIO(sys.stdin.read())
    raw_input = lambda: sys.stdin.readline().rstrip()
pr = lambda *args: sys.stdout.write(" ".join(str(x) for x in args) + "\n")
epr = lambda *args: sys.stderr.write(" ".join(str(x) for x in args) + "\n")
die = lambda *args: pr(*args) ^ exit(0)

read_str = raw_input
read_strs = lambda: raw_input().split()
read_int = lambda: int(raw_input())
read_ints = lambda: map(int, raw_input().split())
read_float = lambda: float(raw_input())
read_floats = lambda: map(float, raw_input().split())

"---------------------------------------------------------------"

n = read_int()

c4 = str(n).count('4')
c7 = str(n).count('7')

n = c4 + c7
c4 = str(n).count('4')
c7 = str(n).count('7')
if c4 + c7 == len(str(n)):
    print "YES"
else:
    print "NO"
