#include "bits/stdc++.h"
using namespace std;
#define int long long
#define FOR(i, a, b) for(int i=(a);i<(b);i++)
#define RFOR(i, a, b) for(int i=(b-1);i>=(a);i--)
#define REP(i, n) for(int i=0; i<(n); i++)
#define RREP(i, n) for(int i=(n-1); i>=0; i--)
#define REP1(i, n) for(int i=1; i<=(n); i++)
#define RREP1(i, n) for(int i=(n); i>=1; i--)
#define ALL(a) (a).begin(),(a).end()
#define UNIQUE_SORT(l) sort(ALL(l)); l.erase(unique(ALL(l)), l.end());
#define CONTAIN(a, b) find(ALL(a), (b)) != (a).end()
#define out(...) printf(__VA_ARGS__)
#if DEBUG
#define debug(...) printf(__VA_ARGS__)
#else
#define debug(...) /* ... */
#endif

void solve();
signed main()
{
#if DEBUG
    std::ifstream in("input.txt");
    std::cin.rdbuf(in.rdbuf());
#endif
    cin.tie(0);
    ios::sync_with_stdio(false);
    solve();
    return 0;
}

/*================================*/
#if DEBUG
#define SIZE 123450
#else
#define SIZE 123450
#endif

int N,C,V;
int DP[SIZE];

void solve() {
    cin>>N>>C>>V;
    REP(i,SIZE)DP[i]=INT_MAX;
    DP[1]=0;
    REP1(i,N) {
        FOR(j,1,N) {
            int k = i*(j+1);
            if (k >= SIZE) break;
            int cost = C+j*V;
            DP[k] = min(DP[k], DP[i]+cost);
        }
    }
    int ans = INT_MAX;
    FOR(i,N,SIZE) {
        ans = min(ans, DP[i]);
    }
    cout << ans << endl;
}