#include<bits/stdc++.h>
using namespace std;
using u64 = uint_least64_t;
using s64 = int_least64_t;
using ll = uint_least64_t;

int main(){
	u64 n;
	cin >> n;

    s64 ans = 5 * n - 12;
    if (ans < 1){
        cout << n << endl;
    }else{
        cout << ans << endl;
    }
	return 0;
}