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 $++.$ It is preferred to use the cin, cout streams or the $\%$I$64$d specificator.

Output

Print on the single line "YES" if n is a nearly lucky number. Otherwise, print $"$NO$"($without the quotes$).$