#pragma GCC optimize(3,"Ofast","inline")
#include <bits/stdc++.h>

#define ios_close std::ios::sync_with_stdio(false), std::cin.tie(nullptr), std::cout.tie(nullptr)

using ll = long long;
using ull = unsigned long long;
using i128 = __int128;
#define Pi  acos(-1.0);
#define PINF 0x3f3f3f3f
#define NINF -0x3f3f3f3f

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

int main(){
#if 0
    ios_close;
#endif

#if 0
    freopen(".in", "r", stdin);
    freopen(".out", "w", stdout);
#endif
    int T = 1;
#if 0
    std::cin >> T;
#endif
    while(T -- ){
        solve();
    }
    return 0;
}