#include <bits/stdc++.h>
using namespace std;
const double eps = 1e-7;
int a[200000];
int n;
bool check(double x) {
  double bound = a[0] + x;
  for (int i = 1, num = 1; i < n; i++)
    if (a[i] > bound) {
      bound = a[i] + x;
      num++;
      if (num > 3) return 0;
    }
  return 1;
}
int main() {
  scanf("%d", &n);
  for (int i = 0; i < n; i++) scanf("%d", &a[i]);
  sort(a, a + n);
  double l = 0, r = 1e10;
  while (r - l > eps) {
    double mid = (l + r) / 2;
    if (check(mid))
      r = mid;
    else
      l = mid;
  }
  printf("%.6f\n%.6f", l / 2, a[0] + l / 2);
  double bound = a[0] + l;
  int num = 1;
  for (int i = 1; i < n; i++)
    if (a[i] > bound + eps) {
      num++;
      printf(" %.6f", a[i] + l / 2);
      bound = a[i] + l;
    }
  for (; num < 3; num++) printf(" %.6f", 0.0);
  puts("");
  return 0;
}
