#include<iostream>
#include<string>
#include<cstdio>
#include<vector>
#include<cmath>
#include<algorithm>
#include<functional>
#include<iomanip>
#include<queue>
#include<ciso646>
#include<random>
#include<map>
#include<set>
#include<complex>
#include<bitset>
#include<stack>
#include<unordered_map>
#include<utility>
#include<tuple>
using namespace std;
typedef long long ll;
typedef unsigned int ui;
const ll mod = 1000000007;
const ll INF = (ll)1000000007 * 1000000007;
typedef pair<int, int> P;
#define stop char nyaa;cin>>nyaa;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define Per(i,sta,n) for(int i=n-1;i>=sta;i--)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
typedef long double ld;
typedef complex<ld> Point;
const ld eps = 1e-8;
const ld pi = acos(-1.0);
typedef pair<ll, ll> LP;

int n,c,v;
ll dp[100010];

vector<int> di(int n){
    vector<int> res={};
    for(int i=1;i*i<=n;i++){
        if(n%i==0){
            res.push_back(i);
            res.push_back(n/i);
        }
    }
    return res;
}

void solve(){
    cin >> n >> c >> v;
    Rep(i,2,2*n+1){
        vector<int> D=di(i);
        ll res=INF;
        for(auto d:D){
            if (d==i) continue;
            ll k=i/d-1;
            res=min(res,dp[d]+k*(ll)v+c);
        }
        dp[i]=res;
        //cout << i << " " << dp[i] << endl;
    }
    ll ans=INF;
    Rep(i,n,2*n+1) ans=min(ans,dp[i]);
    cout << ans << endl;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(50);
    solve();
}