// @Sarievo, URL: https://yukicoder.me/problems/no/2140
#pragma GCC target("avx2")
#pragma GCC optimize("O3","unroll-loops")
#include <bits/stdc++.h>
using namespace std;
// --- Library ---
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
// using mint=modint998244353;
using mint=modint1000000007;
#endif
// --- Type and Alias ---
#define a first
#define b second
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
// find_by_order() - kth largest (0-indexed)
// order_of_key()  - count(Si < k)
template<class T> using indexed_set=tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
template<class T> using indexed_multiset=tree<T,null_type,less_equal<T>,rb_tree_tag,tree_order_statistics_node_update>;
template<class T> using v=vector<T>; template<class T> using vv=v<v<T>>;
template<class T> using minheap=priority_queue<T,v<T>,greater<T>>;
template<class T> using maxheap=priority_queue<T,v<T>,less<T>>;
using ll=long long; using ld=long double;
using vl=v<ll>; using vvl=vv<ll>;
using pl=pair<ll,ll>; using vp=v<pl>;
// --- IO ---
template<typename T> istream&operator>>(istream&is, pair<T,T>&p){is>>p.a>>p.b;return is;}
template<typename T> ostream&operator<<(ostream&os, pair<T,T>&p){os<<p.a<<" "<<p.b;return os;}
template<typename T> istream&operator>>(istream&is, v<T>&a){for(auto&e:a)is>>e;return is;}
template<typename T> ostream&operator<<(ostream&os, v<T>&a){for(auto&e:a)os<<e<<" ";return os;}
#define Nyan ios_base::sync_with_stdio(0);std::cin.tie(0);std::cout.tie(0);std::cout<<fixed;
// --- Macro ---
#define reps(i,start,end_exclusive) for(ll i=(ll)(start);i<(ll)(end_exclusive);++i)
#define rep(i,end_exclusive) reps(i,0,end_exclusive)
#define sum(a) accumulate(all(a),0ll)
#define fore(e,a) for(auto&e:a)
#define all(a) (a).begin(),(a).end()
#define rall(a) (a).rbegin(),(a).rend()
template<class T> auto min(const T&a){return *min_element(all(a));}
template<class T> auto max(const T&a){return *max_element(all(a));}
template<class T,class U> bool chmax(T&x,const U&y){return x<y?x=y,1:0;}
template<class T,class U> bool chmin(T&x,const U&y){return x>y?x=y,1:0;}
template<typename T> inline T abs(const T&x){return (x<0?-x:x);}
template<typename T> inline T sqr(const T&x){return (x*x);}
void yes(bool x){std::cout<<(x?"yes":"no")<<endl;}
void Yes(bool x){std::cout<<(x?"Yes":"No")<<endl;}
void YES(bool x){std::cout<<(x?"YES":"NO")<<endl;}
// --- Vars ---
//       R  D  L  U DR DL UL UR
ll dx[]{+0,+1,+0,-1,+1,+1,-1,-1};
ll dy[]{+1,+0,-1,+0,+1,-1,-1,+1};

/*
a < b < c

*/

void solve(){
  ll a; cin >> a;
  cout << a * 2 - 1 << endl; 
}

signed main(){
  Nyan;
  solve();
}