#include <algorithm>
#include <cstdio>
#include <iostream>
#include <map>
#include <cmath>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
#include <stdlib.h>
#include <stdio.h>
#include <bitset>
#include <cstring>
#include <deque>
using namespace std;
#define FOR(I,A,B) for(int I = (A); I < (B); ++I)
#define CLR(mat) memset(mat, 0, sizeof(mat))
typedef long long ll;
int dp[200005];
int main()
{
  ios::sync_with_stdio(false);
  cin.tie(0);
  int N, C, V; cin >> N >> C >> V;
  FOR(i,0,100005) dp[i] = 1e9;
  dp[1] = 0;
  FOR(i,2,100005) {
    // iの約数の個数
    for(int j = 1; j * j <= i; j++) {
      if(i % j == 0) {
        dp[i] = min(dp[i], dp[j] + (i / j - 1) * V + C);
        int k = i / j;
        dp[i] = min(dp[i], dp[k] + (i / k - 1) * V + C);
      } 
    }
  }
  int ans = 1e9;
  FOR(i,N,100005) ans = min(ans, dp[i]);
  cout << ans << endl;
  return 0;
}