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".
import sys
input = sys.stdin.readline

############ ---- Main Code ---- ############
def main():
	c = 0
	for x in str(inp()):
		if x == "4" or x == "7":
			c += 1
	for x in str(c):
		if not(x == "4" or x == "7"):
			print("NO")
			exit()
	print("YES")



############ ---- Input Functions ---- ############

#For taking integer inputs.
def inp():
    return(int(input()))

# For taking List inputs.
def inlt():
    return(list(map(int,input().split())))

#For taking string inputs
def instr():
    return "".join(insr())

#For taking string inputs as list
def insr():
    s = input()
    return(list(s[:len(s) - 1]))

#For taking space seperated integer variable inputs.
def invr():
    return(map(int,input().split()))

if __name__== "__main__":
    main()

