#include <bits/stdc++.h>
    using namespace std;
    #include <math.h>
    #include <iomanip>
    #include <cstdint>
    #include <string>
    #include <sstream>
    template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
    template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
    #define rep(i,n) for (int i = 0; i < (n); ++i)
    typedef long long ll;
    using P=pair<int,int>;
    const ll INF=1e18;
    const int mod=998244353;
    
    int main(){
      ll n;
      cin>>n;
      if(n<=3){
        cout<<n<<endl;
      }
      else{
        cout<<5ll*(n-3)+3<<endl;
      }
      return 0;
    }