#include <bits/stdc++.h>
#define int long long
using namespace std;
int32_t main() {
ios_base::sync_with_stdio(0);
cin.tie(nullptr);
int n;
cin >> n;
long double sum = 0, st = 0;
vector<int> a(n);
for (int i = 0; i < n; ++i) {
cin >> a[i];
sum += a[i];
}
st = sum / n;
int l = 0, r = n - 1;
long double lv = st, rv = st;
while (l < r) {
long double cur = sum / (r - l + 1);
if (st <= cur) {
sum -= a[r--];
} else {
sum -= a[l++];
}
cur = sum / (r - l + 1);
lv = min(lv, cur);
rv = max(rv, cur);
}
cout << fixed << setprecision(10);
cout << rv - lv << "\n";
return 0;
}
