//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx,avx2,fma")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4.1,sse4.2,sse4a,avx,avx2,popcnt,tune=native")
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <cmath>
#include <vector>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <queue>
#include <ctime>
#include <cassert>
#include <complex>
#include <string>
#include <cstring>
#include <chrono>
#include <random>
#include <bitset>
#include <array>
#include <climits>
using namespace std;
#ifdef LOCAL
#define eprintf(...) {fprintf(stderr, __VA_ARGS__);fflush(stderr);}
#else
#define eprintf(...) 42
#endif
using ll = long long;
using ld = long double;
using uint = unsigned int;
using ull = unsigned long long;
using pii = pair<int, int>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll myRand(ll B) {
return (ull)rng() % B;
}
#define mp make_pair
#define all(x) (x).begin(),(x).end()
clock_t startTime;
double getCurrentTime() {
return (double)(clock() - startTime) / CLOCKS_PER_SEC;
}
ll floor_div(ll x, ll y) {
assert(y != 0);
if (y < 0) {
y = -y;
x = -x;
}
if (x >= 0) return x / y;
return (x + 1) / y - 1;
}
ll ceil_div(ll x, ll y) {
assert(y != 0);
if (y < 0) {
y = -y;
x = -x;
}
if (x <= 0) return x / y;
return (x - 1) / y + 1;
}
const double eps = 1e-10;
bool eq(double x, double y) {
return abs(x - y) < eps;
}
const int N = 200400;
int n;
ll a[N];
ll pref[N];
int cnt[N];
pair<double, int> ev[2 * N];
int bad;
void addOne(int x) {
if (cnt[x] == 0) bad--;
cnt[x]++;
}
void remOne(int x) {
cnt[x]--;
if (cnt[x] == 0) bad++;
}
int main() {
startTime = clock();
// freopen("input.txt", "r", stdin);
// freopen("output.txt", "w", stdout);
scanf("%d", &n);
for (int i = 0; i < n; i++)
scanf("%lld", &a[i]);
for (int i = 0; i < n; i++)
pref[i + 1] = pref[i] + a[i];
double M = (double)pref[n] / n;
ev[0] = mp(M, 0);
for (int k = 1; k < n; k++) {
int l = 0, r = n - k;
while(r - l > 1) {
int x = (l + r) / 2;
if (pref[x + k] - pref[x] < M * k)
l = x;
else
r = x;
}
ev[2 * k - 1] = mp((double)(pref[l + k] - pref[l]) / k, k);
ev[2 * k] = mp((double)(pref[r + k] - pref[r]) / k, k);
}
bad = n;
double ans = a[n - 1] - a[0];
n = 2 * n - 1;
sort(ev, ev + n);
int r = 0;
for (int l = 0; l < n; l++) {
while(r < n && (bad > 0 || eq(ev[r].first, ev[r - 1].first))) {
addOne(ev[r++].second);
}
if (bad > 0) break;
ans = min(ans, ev[r - 1].first - ev[l].first);
remOne(ev[l].second);
}
printf("%.15lf\n", ans);
return 0;
}
