#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define double long double
#define int ll
const int N = (int)1e6 + 10, MOD = (int)1e9 + 7, inf = (int)2e9;
int n, a[N];
ll p[N];
double get(int l, int r) {
return (1.0 * (p[r] - p[l - 1])) / (1.0 * (r - l + 1));
}
double solve_mx(int l, int r, double mn, double mx) {
while(r < n || l > 1) {
if(r + 1 <= n && get(l, r + 1) <= mx) {
r++;
} else {
if(l == 1) {
return inf;
}
l--;
}
mn = min(mn, get(l, r));
}
return mx - mn;
}
double solve_mn(int l, int r, double mn, double mx) {
while(r < n || l > 1) {
if(l - 1 >= 1 && get(l - 1, r) >= mn) {
l--;
} else {
if(r == n) return inf;
r++;
}
mx = max(mx, get(l, r));
}
return mx - mn;
}
void test() {
cin >> n;
for(int i = 1; i <= n; i++) {
cin >> a[i];
p[i] = p[i - 1] + a[i];
}
double res = inf;
for(int i = 1; i <= n; i++) {
res = min(res, solve_mn(i, i, a[i], a[i]));
res = min(res, solve_mx(i, i, a[i], a[i]));
if(i + 1 <= n) {
res = min(res, solve_mn(i, i + 1, a[i], get(i, i + 1)));
res = min(res, solve_mx(i, i + 1, a[i], get(i, i + 1)));
}
if(i - 1 >= 1) {
res = min(res, solve_mn(i - 1, i, get(i - 1, i), a[i]));
res = min(res, solve_mx(i - 1, i, get(i - 1, i), a[i]));
}
}
cout << fixed << setprecision(10) << res << '\n';
}
int32_t main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
int t = 1;
// cin >> t;
while(t--) {
test();
}
}
