#include <bits/stdc++.h>
using namespace std;
const int M = 6666666;
const int INF = 0x3f3f3f3f;
const double PI = acos(-1.0);
const double eps = 1e-7;
const int mod = 1e9 + 7;
int a[105][105];
int main() {
  int n, a, b, c;
  scanf("%d%d%d%d", &n, &a, &b, &c);
  int ans = 0;
  n--;
  if (n == 0) {
    printf("0\n");
    return 0;
  }
  if (a <= c && a <= b) {
    printf("%d\n", n * a);
  } else if (b <= c && b <= a) {
    printf("%d\n", n * b);
  } else {
    ans += min(a, b);
    printf("%d\n", (n - 1) * c + ans);
  }
  return 0;
}
