#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <math.h>
using namespace std;

int main() {
    long long d,tax,f;
    cin >> d;
    tax = d*8;
    f = tax % 100;
    tax /= 100;
    printf("%lld.%02lld\n",d+tax,f);
    return 0;
}