#include <bits/stdc++.h>
using namespace std;
const int N = 5e5 + 5;
int n;
int ar[N];
bool valid(double D) {
  double last = -2e9, stations = 0;
  for (int i = 1; i <= n; i++) {
    if (ar[i] > last + 2 * D) {
      last = ar[i];
      stations++;
    }
  }
  return stations <= 3;
}
int main() {
  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> ar[i];
  }
  sort(ar + 1, ar + n + 1);
  double L = 0, R = 2e9;
  int cnt = 400;
  while (cnt--) {
    double mid = L + (R - L) / 2;
    if (valid(mid)) {
      R = mid;
    } else {
      L = mid;
    }
  }
  cout << fixed << setprecision(6) << R << '\n';
  vector<double> points;
  double last = -1e9;
  for (int i = 1; i <= n; i++) {
    if (ar[i] > last + 2 * R) {
      last = ar[i];
      points.push_back(ar[i] + R);
    }
  }
  for (int i = 0; i < 3; i++) {
    if (i + 1 <= points.size()) {
      cout << points[i] << " ";
    } else {
      cout << 0 << " ";
    }
  }
  return 0;
}
