#include <bits/stdc++.h>
using namespace std;
float dire_temps(clock_t t0) { return (float)(clock() - t0) / CLOCKS_PER_SEC; }
int GCD(int a, int b) { return (b == 0 ? a : GCD(b, a % b)); }
int res(int n, int a, int b, int c) {
  if (n == 1)
    return 0;
  else {
    n--;
    int result = min(a, b);
    n--;
    while (n > 0) {
      result += min(min(a, b), c);
      n--;
    }
    return result;
  }
}
int main() {
  int n, a, b, c;
  cin >> n >> a >> b >> c;
  cout << res(n, a, b, c) << endl;
  return 0;
}
