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".
num=input()
n=int(num)
m=list(num)
cnt4=0
cnt7=0

        
for i in range(len(m)):
    m[i]=int(m[i])
    if m[i]==4:
        cnt4+=1
    elif m[i]==7:
        cnt7+=1
    else:
        pass

ans=cnt4+cnt7
#print(ans)

for i in range(1,18):
    if ans//10**i==0:
        decimal=i
        break
    else:
        pass

digits=[]
def lucky(x):
    if decimal==1:
        if ans==4 or ans==7:
            print('YES')
        else:
            print('NO')
    else:
        for i in range(decimal-1):
            digits.append((x%(10**(i+1)))//(10**i))
    
        for j in range(len(digits)):
            if digits[j]==4:
                digits.remove(4)
                digits.insert(j,0)
            elif digits[j]==7:
                digits.remove(7)
                digits.insert(j,0)
            else:
                pass
        #print(digits)
        if sum(digits)>0:
            print('NO')
        else:
            print('YES')
            

lucky(ans)