#include <bits/stdc++.h> using namespace std; #include <atcoder/all> using namespace atcoder; using ll=long long; using Graph=vector<vector<int>>; #define INF 1000000000 #define MOD 998244353 #define MAX 1000 int main(){ int N; cin>>N; if(N<=6){ cout<<N<<'\n'; }else{ cout<<7*(N-6)+6<<'\n'; } }