#include <bits/stdc++.h>
#include <atcoder/all>
using mint = atcoder::modint998244353;
//using mint = atcoder::modint1000000007;
using namespace atcoder;
using namespace std;

using ll = long long;
using pi = pair<int,int>;
using pl = pair<ll,ll>;
using vi = vector<int>;
using vm = vector<mint>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vpi = vector<pair<int,int>>;
using vpl = vector<pair<ll,ll>>;
#define rep(i,n) for (ll i = 0; i < n; i++)
#define replr(i,l,r) for (ll i = l; i < r; i++)
set<char> abc = {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'};
const int inf =1e9;
const ll infl = 4e18;

template <typename T>
bool chmax(T &a, const T& b) {if (a < b) {a = b;  return true;}return false;}
template <typename T>
bool chmin(T &a, const T& b) {if (a > b) {a = b;  return true;}return false;}
template <typename T>
T max(vector<T> &v) {T m = 0;for (auto x : v) chmax(m, x);return m;}
template <typename T>
T min(vector<T> &v) {T m = inf;for (auto x : v) chmin(m, x);return m;}
template <typename T>
void print(vector<T> &v){for(auto x : v){cout<<x<<' ';}cout<<'\n';}
/*memo

*/


int main(){
    ll N,A,B,C; cin >> N >> A >> B >> C;
    vl dp(2*N,infl);
    dp[1]=0;
    dp[2]=A;
    ll p=1;
    replr(i,2,2*N-1){
        ll n=i;
        ll cost=B;
        while (cost*B<=N*A){
            n*=i;
            if (n>=2*N){
                n%=N;
                n+=N;
            }
            cost*=B;
            chmin(dp[n],dp[i]+cost);
        }
        p*=i;
        if (p>=2*N){
            p%=N;
            p+=N;
        }
        chmin(dp[p],dp[i]+C);
        chmin(dp[i+1],dp[i]+A);
    }
    vl dist(N,infl);
    priority_queue<pl,vector<pl>,greater<pl>> pq;
    rep(i,N){
        pq.push({dp[i+N],i});
    }
    int cnt=0;
    while (!pq.empty()){
        auto [d,n]=pq.top();
        pq.pop();
        cnt++;
        if (dist[n]<=d) continue;
        dist[n]=d;
        if (dist[(n+1)%N]>d+A){
            dist[(n+1)%N]=d+A;
            pq.push({d+A,(n+1)%N});
        }
        ll cost=B;
        ll nn=n;
        while (cost*B<=N*A){
            nn*=n;
            nn%=N;
            cost*=B;
            if (dist[nn]>d+cost){
                dist[nn]=d+cost;
                pq.push({d+cost,nn});
            }
        }
    }
    ll ans=infl;
    rep(i,N){
        chmin(ans,dist[i]+C);
    }
    chmin(ans,dist[0]);
    cout << ans << '\n';

}