#include <bits/stdc++.h> using namespace std; using ll = long long; using P = pair<ll,ll>; #define fix(x) fixed << setprecision(x) #define asc(x) x, vector<x>, greater<x> #define rep(i, n) for(ll i = 0; i < n; i++) #define all(x) (x).begin(),(x).end() template<class T>bool chmin(T&a, const T&b){if(a>b){a=b;return 1;}return 0;} template<class T>bool chmax(T&a, const T&b){if(a<b){a=b;return 1;}return 0;} int main(){ cin.tie(nullptr); ios::sync_with_stdio(false); ll n; cin >> n; cout << n*2-1 << '\n'; return 0; }