#include<bits/stdc++.h> #define int double using namespace std; main(){ int n; cin>>n; printf("%.1lf",((2*n+3)/n/n)*100); cout<<'%'; return 0; }

#include<bits/stdc++.h>
#define int double
using namespace std;
 main(){
    int n;
    cin>>n;
    printf("%.1lf",((2*n+3)/n/n)*100);
    cout<<'%';
    return 0;
}