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".
# A. Nearly Lucky Number
# time limit per test2 seconds
# memory limit per test256 megabytes
# inputstandard input
# outputstandard output
# 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
# inputCopy
# 40047
# outputCopy
# NO
# inputCopy
# 7747774
# outputCopy
# YES
# inputCopy
# 1000000000000000000
# outputCopy
# NO
check = ["4","7"]
def isLuckyNum(n):
    for i in str(n):
        if i not in check:
            return False
    return True

def isNLN(n):
    return True if isLuckyNum(str(n).count("4")+str(n).count("7")) else False

s = int(input())
if isNLN(s):
    print("YES")
else:
    print("NO")
