#include <bits/stdc++.h>
using namespace std;
const long long INF = 1000000000000000000;
vector<vector<long long>> matmul(vector<vector<long long>> A, vector<vector<long long>> B){
  int N = A.size();
  vector<vector<long long>> C(N, vector<long long>(N, INF));
  for (int i = 0; i < N; i++){
    for (int j = 0; j < N; j++){
      for (int k = 0; k < N; k++){
        C[i][k] = min(C[i][k], A[i][j] + B[j][k]);
      }
    }
  }
  return C;
}
vector<vector<long long>> matpow(vector<vector<long long>> A, long long K){
  int N = A.size();
  vector<vector<long long>> ans(N, vector<long long>(N, INF));
  for (int i = 0; i < N; i++){
    ans[i][i] = 0;
  }
  while (K > 0){
    if (K % 2 == 1){
      ans = matmul(ans, A);
    }
    A = matmul(A, A);
    K /= 2;
  }
  return ans;
}
int main(){
  long long N;
  int A, B;
  cin >> N >> A >> B;
  vector<vector<long long>> mat = {{A - B, -A + B}, {-A - B, A + B}};
  mat = matpow(mat, N - 1);
  cout << min({-B + mat[0][0], -B + mat[0][1], B + mat[1][0], B + mat[1][1]}) << endl;
}