#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
typedef long long ll;
typedef pair<ll,ll> P;
typedef modint1000000007 mint;
#define rep(i,a,b) for(ll i=a;i<b;i++)
#define rrep(i,a,b) for(ll i=a;i>=b;i--)
const ll inf=1e18;
ll n;
int main(void){
    cin.tie(0);
    ios::sync_with_stdio(0);
    cin>>n;
    if(n<=3){
        cout<<n<<endl;
    }else{
        cout<<5*(n-3)+3<<endl;
    }

}