#include <bits/stdc++.h>
using namespace std;
const long double eps = 1e-9;
const int inf = (1 << 30) - 1;
const long long inf64 = ((long long)1 << 62) - 1;
const long double pi = 3.1415926535897932384626433832795;
template <class T>
T sqr(T x) {
  return x * x;
}
const int nmax = 300300;
int n;
double a[nmax];
int main() {
  scanf("%d", &n);
  for (int i = 0; i < (int)(n); i++) scanf("%lf", &a[i]);
  sort(a, a + n);
  double l, r;
  l = 0, r = 1e10;
  for (int i = 0; i < (int)(100); i++) {
    double m = (l + r) / 2;
    double now = a[0] - 1;
    int res = 0;
    for (int j = 0; j < (int)(n); j++)
      if (a[j] > now) {
        res++;
        now = a[j] + m * 2;
      }
    if (res <= 3)
      r = m;
    else
      l = m;
  }
  printf("%0.9lf\n", l);
  double now = a[0] - 1;
  vector<double> w;
  for (int j = 0; j < (int)(n); j++) {
    if (a[j] > now) {
      w.push_back(a[j] + l);
      now = a[j] + l * 2;
    }
  }
  while (w.size() < 3) w.push_back(0);
  sort(w.begin(), w.end());
  for (int i = 0; i < (int)(w.size()); i++) printf("%0.9lf ", w[i]);
  puts("");
  return 0;
}
