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 + 100;
int n;
long double arr[N];
long double f(long double x) {
  long double minS = 0, maxS = 0, curS = 0, ans = 0;
  for (int i = 0; i < n; i++) {
    curS += arr[i] - x;
    ans = max(ans, abs(curS - minS));
    ans = max(ans, abs(curS - maxS));
    minS = min(minS, curS);
    maxS = max(maxS, curS);
  }
  return ans;
}
int main() {
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> arr[i];
  }
  long double l = -3e9, r = 3e9;
  for (int i = 0; i < 200; i++) {
    long double mid1 = (l * 2 + r) / 3, mid2 = (l + r * 2) / 3;
    long double f1 = f(mid1), f2 = f(mid2);
    if (f1 > f2)
      l = mid1;
    else
      r = mid2;
  }
  cout.precision(20);
  cout << fixed << f((l + r) / 2) << "\n";
  return 0;
}
