#include<bits/stdc++.h>
using namespace std;
const int maxn = 2e5;
const int inf = 1e9;
long double n, a[maxn + 1];
namespace sub1{
long double recur(int i, int j, long double l, long double r){
long double cur = 0;
for (int ind = i; ind <= j; ++ind){
cur += (long double) a[ind];
}
cur /= (long double) (j - i + 1);
l = min(l, cur);
r = max(r, cur);
if (i == j)
return r - l;
return min(recur(i + 1, j, l, r), recur(i, j - 1, l, r));
}
long double solve(){
return recur(1, n, inf + 1, -1);
}
}
namespace sub3{
long double pre[maxn + 1];
long double solve(){
long double res = inf + 1;
for (int i = 1; i <= n; ++i){
pre[i] = pre[i - 1] + a[i];
}
for (int i = 1; i <= n; ++i){
long double l = a[i], r = a[i];
int u = i, v = i;
while(u != 1 || v != n){
if (u == 1){
v++;
r = max(r, (pre[v] - pre[u - 1]) / (long double) (v - u + 1));
}
else if (v == n){
u--;
l = min(l, (pre[v] - pre[u - 1]) / (long double) (v - u + 1));
}
else{
long double move_left = (pre[v] - pre[u - 2]) / (long double) (v - u + 2);
long double move_right = (pre[v + 1] - pre[u - 1]) / (long double) (v - u + 2);
if (l - move_left < move_right - r){
u--;
l = min(l, move_left);
}
else{
v++;
r = max(r, move_right);
}
}
}
// cout << l << ' ' << r << '\n';
res = min(res, r - l);
}
return res;
}
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> n;
for (int i = 1; i <= n; ++i){
cin >> a[i];
}
cout << fixed << setprecision(10) << sub3::solve() << '\n';
// if (n <= 20){
// cout << fixed << setprecision(9) << sub1::solve();
// }
// else if (n <= 2000){
// cout << fixed << setprecision(9) << sub3::solve();
// }
}
