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;
int n;
double l = -10000.0, r = 10000.0, mid, shu[200005], shu1[200005];
double f1() {
  double ans = 0, sum = 0;
  for (int i = 1; i <= n; i++) {
    sum = sum + shu1[i];
    if (sum < 0) sum = 0;
    ans = max(ans, sum);
  }
  return ans;
}
double f(double x) {
  double ans;
  for (int i = 1; i <= n; i++) shu1[i] = shu[i] - x;
  ans = f1();
  for (int i = 1; i <= n; i++) shu1[i] = -shu1[i];
  ans = max(ans, f1());
  return ans;
}
int main() {
  cin >> n;
  for (int i = 1; i <= n; i++) cin >> shu[i];
  for (int i = 1; i <= 100; i++) {
    double mid1 = l + (r - l) / 3;
    double mid2 = r - (r - l) / 3;
    if (f(mid1) < f(mid2))
      r = mid2;
    else
      l = mid1;
  }
  cout << f(l);
}
