#include <bits/stdc++.h>
using namespace std;
vector<double> res;
bool check(vector<int> a, double x) {
  vector<double> ans;
  for (int i : a) {
    if (ans.size() == 0 || ans.back() + x < i) {
      ans.push_back(i + x);
    }
  }
  if (ans.size() > 3) return false;
  res = ans;
  return true;
}
int main() {
  ios::sync_with_stdio(false);
  int n;
  cin >> n;
  vector<int> a(n);
  for (int i = 0; i < n; i++) cin >> a[i];
  sort(a.begin(), a.end());
  double left = 0.0, right = 1000000000.0;
  while (abs(right - left) > 0.0000001) {
    double mid = (left + right) / 2;
    if (check(a, mid))
      right = mid;
    else
      left = mid;
  }
  printf("%.6lf\n", left);
  for (int i = 0; i < res.size(); i++) printf("%.6lf ", res[i]);
  for (int i = 0; i < 3 - res.size(); i++) printf("%.6lf ", res.back());
  printf("\n");
}
