#include <bits/stdc++.h>
using namespace std;
const int cpt = 10000000;
long long x[200003];
long long nc[5];
int n;
bool out;
bool can(long long r) {
  int now = 1;
  nc[1] = x[0] + r;
  for (int i = 0; i < n; ++i) {
    if (x[i] > nc[now] + r) nc[++now] = x[i] + r;
    if (now > 3) return false;
  }
  while (now < 3) nc[++now] = nc[1];
  return true;
}
int main() {
  out = false;
  cin >> n;
  for (int i = 0; i < n; ++i) scanf("%lld", &x[i]), x[i] *= cpt;
  sort(x, x + n);
  long long l = 0, r = 20000000000000000ll, m;
  while (l < r) {
    m = (l + r) >> 1;
    if (can(m))
      r = m;
    else
      l = m + 1;
  }
  long double res = l;
  res /= cpt;
  printf("%.7Lf\n", res);
  out = true;
  can(l);
  for (int i = 1; i <= 3; ++i) {
    res = nc[i];
    res /= cpt;
    printf("%.7Lf ", res);
  }
}
