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 double e = exp(1.0);
const double INF = 1e9;
const double eps = 1e-11;
double maxX = -INF;
double minX = INF;
const int N = 200000 + 10;
double a[N];
double fx(double v, int n) {
  double tmp = a[0] - v;
  double neg_tmp = a[0] - v;
  bool flag = false;
  if (a[0] < v) flag = true;
  for (int i = 1; i < n; i++) {
    if (a[i] < v) flag = true;
    tmp += a[i] - v;
    if (tmp < a[i] - v) tmp = a[i] - v;
    neg_tmp = max(tmp, neg_tmp);
  }
  if (flag) {
    maxX = v - a[0];
    tmp = v - a[0];
    for (int i = 1; i < n; i++) {
      tmp += v - a[i];
      if (tmp < v - a[i]) tmp = v - a[i];
      maxX = max(tmp, maxX);
    }
  }
  return max(neg_tmp, maxX);
}
int main() {
  int n;
  cin >> n;
  double xi = 0;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    maxX = max(a[i], maxX);
    maxX = max(-a[i], maxX);
    minX = min(a[i], minX);
  }
  double L = -INF;
  double R = INF;
  while (L + eps < R) {
    double mid_L = (2 * L + R) / 3;
    double mid_R = (L + 2 * R) / 3;
    double res_L = fx(mid_L, n);
    double res_R = fx(mid_R, n);
    if (res_L > res_R)
      L = mid_L;
    else
      R = mid_R;
  }
  double answer = (L + R) / 2;
  cout << fixed << setprecision(7) << fx(answer, n);
  return 0;
}
