#include <bits/stdc++.h>
int n;
int dp[110][110];
int dfs(int x) {
  if (n == 1) return 0;
  int M, sum = 0, u;
  for (int k = 0; k < n - 1; k++) {
    M = 9999999;
    for (int i = 1; i <= 3; i++)
      if (dp[x][i] < M && i != x) {
        M = dp[x][i];
        u = i;
      }
    x = u;
    sum += M;
  }
  return sum;
}
int main() {
  int a, b, c;
  while (~scanf("%d %d %d %d", &n, &a, &b, &c)) {
    memset(dp, 0, sizeof(dp));
    dp[1][2] = dp[2][1] = a;
    dp[1][3] = dp[3][1] = b;
    dp[2][3] = dp[3][2] = c;
    int s = dfs(1);
    printf("%d\n", s);
  }
}
