## Algorithm

A. Nearly Lucky Number
time limit per test
2 seconds
memory limit per test
256 megabytes
https://codeforces.com/problemset/problem/110/A
input
standard input
output
standard output

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 ะก++. 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
Copy
`40047`
Output
Copy
`NO`
Input
Copy
`7747774`
Output
Copy
`YES`
Input
Copy
`1000000000000000000`
Output
Copy
`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".

## Code Examples

### #1 Code Example with C++ Programming

```Code - C++ Programming```

``````#include<iostream>
using namespace std;

int main(){
long long n;
cin>>n;
int check = 0;
int rem;
while(n != 0){
rem = n%10;
n /= 10;
if(rem == 7 || rem == 4){
check++;
}

}
if(check != 4 && check != 7){
cout<<"NO";
}
else{
cout<<"YES";
}
return 0;
}``````
Copy The Code &

Input

cmd
40047

Output

cmd
NO