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 L(number):
    if number == 0 :
        return False
    while number > 0 :
        x = number % 10 
        number /= 10 
        if  not( x == 7 or x == 4 ) :
            return False    
    return True

x = int(input())
C_7=0
C_4=0
while x > 0 :
    y=x%10
    x/=10
    if y == 7:
        C_7+=1
    elif y==4:
        C_4+=1
        
#print C_7,C_4,C        
if L(C_7+C_4) :
    print 'YES'
else :
    print 'NO'
