16 lines
265 B
C++
16 lines
265 B
C++
#include<bits/stdc++.h>
|
|
using namespace std;
|
|
|
|
int main()
|
|
{
|
|
long long n;
|
|
int count=0;
|
|
cin>>n;
|
|
while(n!=0)
|
|
{
|
|
if(n%10==4 || n%10==7) count++;
|
|
n=n/10;
|
|
}
|
|
if(count==4 || count==7) cout<<"YES"<<endl;
|
|
else cout<<"NO"<<endl;
|
|
} |