#include <bits/stdc++.h>
using namespace std;

using T = long long;

void min_self(T &a, T b) { a = min(a, b); }

const long long inf = 1LL << 62;

struct Matrix {
  vector<vector<T>> data;
  int n;
  Matrix(int _n, T val = 0) : n(_n) { data = vector(n, vector<T>(n, val)); }

  Matrix(vector<vector<T>> _data) {
    n = _data.size();
    data = _data;
  }

  Matrix operator*(const Matrix &b) const {
    Matrix c = Matrix(n, inf);
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < n; j++) {
        for (int k = 0; k < n; k++) {
          min_self(c.data[i][k], data[i][j] + b.data[j][k]);
        }
      }
    }
    return c;
  }

  Matrix power(long long k) {
    Matrix res = Matrix(n);
    Matrix tmp = (*this);
    for (int i = 0; i < n; i++) {
      res.data[i][i] = 1;
    }
    while (k > 0) {
      if (k & 1) {
        res = res * tmp;
      }
      tmp = tmp * tmp;
      k >>= 1;
    }
    return res;
  }
};

int main() {
  iostream::sync_with_stdio(0), cin.tie(0), cout.tie(0);

  long long n, a, b;
  cin >> n >> a >> b;
  vector<vector<long long>> m;
  {
    vector<vector<long long>> initial = {{a + b, -a + b}, {-a - b, a - b}};
    m = Matrix(initial).power(n - 1).data;
  }
  cout << min({b + m[0][0], -b + m[0][1], b + m[1][0], -1 + m[1][1]}) << '\n';

  return 0;
}