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".
#akash mandal: jalpaiguri government engineering college
#take a look on special cases: test cases
import sys,math

def ii(): return int(input())
def mii(): return map(int,input().split())
def lmii(): return list(mii())

def main():
    s=input()
    s4=s.count("4");s7=s.count("7")
    sd=s4+s7;r=str(sd)
    rr=list(set(r))
    rr.sort()
    if len(rr)>2:
        print("NO")
        exit(0)
    if len(rr)==1:
        if rr[0]=="4" or rr[0]=="7":
            print("YES")
        else:
            print("NO")
        exit(0)
    if len(rr)==2:
        if (rr[0]=="4" and rr[1]=="7"):
            print("YES")
        else:
            print("NO")
    
    
        
        
     
        
if __name__=="__main__":
    main() 