#include <bits/stdc++.h>
using namespace std;
const int OO = (int)1e8;
double arr[200001];
int t;
bool isok(double x) {
  double pos = 0;
  int tot = 0;
  while (1) {
    int idx = upper_bound(arr, arr + t, pos) - arr;
    if (idx >= t) break;
    tot++;
    pos = arr[idx] + 2 * x;
  }
  return tot <= 3;
}
void build(double x) {
  double pos = 0;
  int tot = 0;
  while (1) {
    int idx = upper_bound(arr, arr + t, pos) - arr;
    if (idx >= t) break;
    if (tot) printf(" ");
    printf("%.6lf", arr[idx] + x);
    tot++;
    pos = arr[idx] + 2 * x;
  }
  while (tot < 3) {
    tot++;
    printf(" %.6lf", pos);
  }
}
int main() {
  scanf("%d", &t);
  double end = 0;
  for (int i = 0; i < t; ++i) {
    scanf("%lf", arr + i);
    end += arr[i];
  }
  sort(arr, arr + t);
  double st = 0, sz = end / 2, ret;
  while (sz > 1e-7) {
    double mid = st + sz;
    if (isok(mid)) {
      ret = mid;
    } else
      st = mid;
    sz *= 0.5;
  }
  ret *= 1000000;
  ret = round(ret);
  ret /= 1000000;
  if (ret < 1e-7)
    printf("0\n");
  else
    printf("%.6lf\n", ret);
  build(ret);
  return 0;
}
