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 is_happy(k):
	kstr = str(k)
	lk = len(kstr)
	res = True
	for i in xrange(0, lk):
		if not ((kstr[i] == '4') or(kstr[i] == '7')):
			res = False
			break
	return res


nstr = raw_input().strip()
k = 0
ln = len(nstr)
for i in xrange(0, ln):
	if (nstr[i] == '4') or (nstr[i] == '7'):
		k += 1
		
if is_happy(k):
	print "YES"
else:
	print "NO"


