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".

def look_for(Number, lenn, Count):

    if lenn == 0:

        return Count

    else:

        if Number[0] == '4' or Number[0] == '7':
            Count = Count +1

            return look_for(Number[1:], lenn-1, Count)

        else:
            return look_for(Number[1:], lenn-1, Count)

def is_lucky(Str, lenn):

    if lenn == 0:
        return True

    else:

        if Str[0] != '4' and Str[0] != '7':
            return False

        else:
            return is_lucky(Str[1:], lenn-1)


def main():

    Number = raw_input()

    Count = look_for(Number, len(Number), 0)

    #print(str(Count), '  ', str(len(str(Count))))

    if is_lucky(str(Count), len(str(Count))):
        print ('YES')

    else:
        print('NO')
    
	return 0

if __name__ == '__main__':
	main()

