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 N = 2e5 + 5;
const double eps = 1e-12;
int a[N];
int main() {
  int n;
  scanf("%d", &n);
  for (int i = 0; i < n; i++) scanf("%d", &a[i]);
  double Max, Min, now;
  double l = -1e4, r = 1e4;
  while (r - l > eps) {
    double m = (l + r) / 2;
    now = 0;
    Max = -1e9;
    for (int i = 0; i < n; i++) {
      now += a[i] - m;
      if (now > Max) Max = now;
      if (now < 0) now = 0;
    }
    now = 0;
    Min = 1e9;
    for (int i = 0; i < n; i++) {
      now += a[i] - m;
      if (now < Min) Min = now;
      if (now > 0) now = 0;
    }
    if (Max + Min > 0)
      l = m;
    else
      r = m;
  }
  printf("%.10f", Max);
  return 0;
}
