#include <bits/stdc++.h>
using namespace std;
int n, x[200005];
double ans;
bool check(double k) {
  int tot = 0;
  double cnt = -1;
  for (int i = 0; i < n; i++) {
    if (x[i] > cnt) tot++, cnt = x[i] * 1.0 + k * 2;
  }
  return tot <= 3;
}
int main() {
  cin >> n;
  for (int i = 0; i < n; i++) cin >> x[i];
  sort(x, x + n);
  int l = 0, r = 1000000000, mid;
  while (l <= r) {
    mid = (l + r) / 2;
    if (check(mid * 0.5))
      ans = mid * 0.5, r = mid - 1;
    else
      l = mid + 1;
  }
  cout << fixed << setprecision(6) << ans << endl;
  double las, cnt = -1, tot = 0;
  for (int i = 0; i < n; i++) {
    if (x[i] > cnt) {
      tot++;
      cout << fixed << setprecision(6) << x[i] + ans << " ";
      las = x[i] + ans;
      cnt = x[i] * 1.0 + ans * 2;
    }
  }
  for (int i = 0; i < 3 - tot; i++) cout << las << " ";
  return 0;
}
