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;
long long gcd(long long a, long long b) {
  while (b) {
    a %= b;
    swap(a, b);
  }
  return a;
}
long double ans = 0;
long double check(vector<long long>& mas, long double& x) {
  long long n = mas.size();
  long double mx1 = mas[0] - x, sum = 0, min_sum = 0;
  for (long long r = 0; r < n; r++) {
    sum += mas[r] - x;
    mx1 = max(mx1, sum - min_sum);
    min_sum = min(min_sum, sum);
  }
  long double mx2 = mas[0] - x;
  sum = 0;
  min_sum = 0;
  for (long long r = 0; r < n; r++) {
    sum += mas[r] - x;
    mx2 = min(mx2, sum - min_sum);
    min_sum = max(min_sum, sum);
  }
  return max(abs(mx1), abs(mx2));
}
void solve() {
  long long n;
  cin >> n;
  vector<long long> mas(n);
  for (long long i = 0; i < n; i++) {
    cin >> mas[i];
  }
  long double l = -10001, r = 10001;
  for (long long i = 0; i < 100; i++) {
    long double lm = (2 * l + r) / 3;
    long double rm = (l + 2 * r) / 3;
    long double a = check(mas, lm), b = check(mas, rm);
    if (a > b) {
      l = lm;
      ans = a;
    } else {
      r = rm;
      ans = b;
    }
  }
  cout << fixed << setprecision(20) << ans;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long t;
  t = 1;
  while (t--) {
    solve();
  }
  return 0;
}
