#include <bits/stdc++.h>
int dx[] = {-1, -1, -1, 0, 1, 1, 1, 0};
int dy[] = {-1, 0, 1, 1, 1, 0, -1, -1};
using namespace std;
long long power(long long a, long long p, long long M) {
  long long r = 1;
  a = a % M;
  while (p > 0) {
    if (p % 2) r = (r * a) % M;
    a = (a * a) % M;
    p /= 2;
  }
  return r;
}
long long gcd(long long a, long long b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
void solve() {
  int n, a, b, c;
  cin >> n >> a >> b >> c;
  n--;
  if (!n) {
    cout << 0 << endl;
    return;
  }
  if (c <= a && c <= b) {
    cout << min(a, b) + (n - 1) * c << endl;
  } else if (a > b) {
    cout << n * b << endl;
  } else {
    cout << n * a << endl;
  }
}
int main() {
  solve();
  return 0;
}
