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 a[300005];
int n;
long double test(long double x) {
  long double sum = 0;
  long double mn = 0;
  long double mx = 0;
  long double ret = 0;
  for (int i = 0; i < n; i++) {
    sum += (a[i] - x);
    ret = max(ret, abs(sum - mn));
    ret = max(ret, abs(sum - mx));
    mn = min(mn, sum);
    mx = max(mx, sum);
  }
  return ret;
}
int main() {
  cin >> n;
  for (int i = 0; i < n; i++) cin >> a[i];
  long double s = -10000, e = 10000;
  while (e - s > 1e-9) {
    long double t1 = s + (e - s) / 3;
    long double t2 = s + (e - s) * 2 / 3;
    long double v1 = test(t1);
    long double v2 = test(t2);
    if (v1 < v2) {
      e = t2;
    } else {
      s = t1;
    }
  }
  cout << test(s);
}
