#include <bits/stdc++.h>
using namespace std;
const double eps = 1e-7;
const double pi = acos(-1.0);
int dblcmp(double d) {
  if (fabs(d) < eps) return 0;
  return d > eps ? 1 : -1;
}
double a[300000];
int n;
int main() {
  int i, j, k;
  scanf("%d", &n);
  for (i = 0; i < n; i++) scanf("%lf", a + i);
  sort(a, a + n);
  double low = 0, high = 1e10, mid;
  int cnt = 100;
  while (cnt--) {
    mid = (low + high) / 2.0;
    int tmp = 0;
    double pre = -1e10;
    for (i = 0; i < n; i++) {
      while (dblcmp(pre - a[i]) >= 0 && i < n) i++;
      if (i == n) break;
      tmp++;
      pre = a[i] + 2 * mid;
    }
    if (tmp <= 3) {
      high = mid;
    } else {
      low = mid;
    }
  }
  mid += eps;
  printf("%lf\n", mid);
  double pre = -1e10;
  int tmp = 0;
  for (i = 0; i < n; i++) {
    while (dblcmp(pre - a[i]) >= 0 && i < n) i++;
    if (i == n) break;
    tmp++;
    pre = a[i] + 2 * mid;
    printf("%lf", pre - mid);
    if (tmp < 3)
      printf(" ");
    else {
      puts("");
      break;
    }
  }
  if (tmp == 2) {
    printf("%lf\n", 1.5e9);
  } else if (tmp == 1) {
    printf("%lf %lf\n", 1.5e9, 1.9e9);
  }
  return 0;
}
