// #pragma GCC target("avx2")
// #pragma GCC optimize("O3")
// #include <x86intrin.h>
#include <bits/stdc++.h>
#include <chrono>
#include <random>
// @author: Vlapos
namespace operators
{
template <typename T1, typename T2>
std::istream &operator>>(std::istream &in, std::pair<T1, T2> &x)
{
in >> x.first >> x.second;
return in;
}
template <typename T1, typename T2>
std::ostream &operator<<(std::ostream &out, std::pair<T1, T2> x)
{
out << x.first << " " << x.second;
return out;
}
template <typename T1>
std::istream &operator>>(std::istream &in, std::vector<T1> &x)
{
for (auto &i : x)
in >> i;
return in;
}
template <typename T1>
std::ostream &operator<<(std::ostream &out, std::vector<T1> &x)
{
for (auto &i : x)
out << i << " ";
return out;
}
template <typename T1>
std::ostream &operator<<(std::ostream &out, std::set<T1> &x)
{
for (auto &i : x)
out << i << " ";
return out;
}
}
// name spaces
using namespace std;
using namespace operators;
// end of name spaces
// defines
#define ll long long
#define ull unsigned long long
#define pb push_back
#define mp make_pair
#define pii pair<int, int>
#define pll pair<ll, ll>
#define f first
#define s second
#define uint unsigned int
#define all(vc) vc.begin(), vc.end()
// end of defines
// usefull stuff
void boost()
{
ios_base ::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
}
inline int getbit(int &x, int &bt) { return (x >> bt) & 1; }
const int dx4[4] = {-1, 0, 0, 1};
const int dy4[4] = {0, -1, 1, 0};
const int dx8[8] = {-1, -1, -1, 0, 0, 1, 1, 1};
const int dy8[8] = {-1, -0, 1, -1, 1, -1, 0, 1};
const ll INF = (1e18) + 500;
const int BIG = (1e9) * 2 + 100;
const int MAXN = (1e5) + 5;
const int MOD7 = (1e9) + 7;
const int MOD9 = (1e9) + 9;
const uint MODFFT = 998244353;
#define int ll
struct test
{
vector<int> pref;
long double P;
void solve(int testcase)
{
boost();
int n;
cin >> n;
P = 0;
pref.resize(n + 1);
vector<int> a(n);
cin >> a;
for (int i = 1; i <= n; ++i)
pref[i] = pref[i - 1] + a[i - 1];
P = (long double)pref[n] / n;
vector<pair<long double, int>> vals;
vals.pb({P, n});
for (int len = n - 1; len > 0; --len)
{
// [L ... L + len) <= P
// [R ... R + len) > P
int L = 0;
int R = n - len;
while (R - L > 1)
{
int M = (L + R) >> 1;
if ((long double)(pref[M + len] - pref[M]) / len <= P)
L = M;
else
R = M;
}
vals.pb({(long double)(pref[L + len] - pref[L]) / len, len});
vals.pb({(long double)(pref[R + len] - pref[R]) / len, len});
}
sort(all(vals));
vector<int> was(n + 1);
int r = 0;
int cnt = 0;
long double res = 1e9 * 1e5;
for (int l = 0; l < vals.size(); ++l)
{
while (cnt != n and r < vals.size())
{
cnt += (int)!(was[vals[r].s]);
was[vals[r].s]++;
r++;
}
if (cnt == n)
res = min(res, vals[r - 1].f - vals[l].f);
was[vals[l].s]--;
cnt -= (int)!(was[vals[l].s]);
}
cout << fixed << setprecision(10);
cout << res << "\n";
}
};
main()
{
boost();
int q = 1;
// cin >> q;
for (int i = 0; i < q; i++)
{
test t;
t.solve(i);
}
return 0;
}
//[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]//
// //
// Coded by Der_Vlἀpos //
// //
//[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]//
