#define  _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <algorithm>
#include <utility>
#include <functional>
#include <cstring>
#include <queue>
#include <stack>
#include <math.h>
#include <iterator>
#include <vector>
#include <string>
#include <set>
#include <math.h>
#include <iostream> 
#include <random>
#include<map>
#include <iomanip>
#include <time.h>
#include <stdlib.h>
#include <list>
#include <typeinfo>
#include <list>
#include <set>
#include <cassert>
#include<fstream>
#include <unordered_map>  
using namespace std;
#define eps 0.00000001
#define LONG_INF 10000000000000000
#define GOLD 1.61803398874989484820458
#define MAX_MOD 1000000007
#define REP(i,n) for(long long i = 0;i < n;++i)
int main() {
	long long n, v, c;
	cin >> n >> c >> v;
	long long now = 1;
	long long board = 1;
	long long ans = c;
	while (now < n) {
		now += board;
		ans += v;
		if (now >= n) break;
		long long remain = n - now;
		long long cost = (remain + board - 1) / board;
		cost *= v;
		cost -= c;
		long long pre_board = now;
		cost -= ((remain + pre_board - 1) / pre_board)*v;
		if (cost >= 0) {
			ans += c;
			board = now;
		}
	}
	cout << ans << endl;
	return 0;
}