#include <bits/stdc++.h>
using namespace std;
int main() {
  int v;
  cin >> v;
  int a, b, c;
  cin >> a >> b >> c;
  int ar[4][4];
  ar[1][1] = 100000;
  ar[1][2] = b;
  ar[1][3] = a;
  ar[2][1] = b;
  ar[2][2] = 100000;
  ar[2][3] = c;
  ar[3][1] = a;
  ar[3][2] = c;
  ar[3][3] = 100000;
  int dis = 0;
  int vis = 1;
  if (v == 1) cout << 0;
  if (v == 2) cout << min(a, b);
  if (v >= 3) {
    for (int i = 1; i <= v - 1; i++) {
      int min1 = 100000;
      int flag = 0;
      if (ar[vis][1] < min1) {
        min1 = ar[vis][1];
        flag = 1;
      }
      if (ar[vis][2] < min1) {
        min1 = ar[vis][2];
        flag = 2;
      }
      if (ar[vis][3] < min1) {
        min1 = ar[vis][3];
        flag = 3;
      }
      if (flag == 1) vis = 1;
      if (flag == 2) vis = 2;
      if (flag == 3) vis = 3;
      dis = dis + min1;
    }
    cout << dis;
  }
  return 0;
}
