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 isLucky(io):
    while len(io) > 0:
        if io[0] == "4" or io[0] == "7":
            io.remove(io[0])

        else:
            break

    if len(io) == 0:
        return True

    else:
        return False


lst = []
for i in range(0, 1001):
    io = list(str(i))
    if isLucky(io):
        lst.append(i)

print(lst)"""

pn = int(input())
n = list(str(pn))
listOfLuckyNumbers = [4, 7, 44, 47, 74, 77, 444, 447, 474, 477, 744, 747, 774, 777]
olist = []

for i in n:
    if i == "4" or i == "7":
        olist.append(i)

#print(olist)

if len(olist) in listOfLuckyNumbers:
    print("YES")

else:
    print("NO")