10
-405 -230 252 -393 -390 -259 97 163 81 -129
 3
10000 -10000 10000
 1
-10000
 20
-16 -23 29 44 -40 -50 -41 34 -38 30 -12 28 -44 -49 15 50 -28 38 -2 0

702.333333333333712
 10000.000000000016371
 0.000000000000000
 113.875000000000043

#include <bits/stdc++.h>
using namespace std;
const int mn = 2e5 + 10;
int n;
long double a[mn], p[mn];
long double eps = 1e-8;
long double val(long double x) {
  long double sm = 0, lar = 0, ans = 0;
  for (int i = 1; i <= n; i++) {
    p[i] = p[i - 1] + a[i] - x;
    sm = min(sm, p[i]);
    lar = max(lar, p[i]);
    ans = max(ans, max(abs(p[i] - sm), abs(p[i] - lar)));
  }
  return ans;
}
int main() {
  cin.tie(0);
  cin.sync_with_stdio(0);
  cin >> n;
  for (int i = 1; i <= n; i++) cin >> a[i];
  long double cur = -2e12;
  for (long double i = 4e12; i >= 1e-8; i /= 2) {
    if (val(cur + i + eps) < val(cur + i)) cur += i;
  }
  cout << val(cur);
}
