#include <bits/stdc++.h>
using namespace std;
int n;
vector<int> a(n);
double f(double x) {
  double mx = 0, sum1 = 0, sum2 = 0;
  for (int i = 0; i < n; ++i) {
    sum1 = max(0., sum1 + a[i] - x);
    sum2 = max(0., sum2 + x - a[i]);
    mx = max({mx, sum1, sum2});
  }
  return mx;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cin >> n;
  a.resize(n);
  for (int i = 0; i < n; ++i) {
    cin >> a[i];
  }
  double l = -1e4, r = 1e4;
  for (int rep = 0; rep < 200; ++rep) {
    double mid1 = l + (r - l) / 3;
    double mid2 = r - (r - l) / 3;
    if (f(mid1) > f(mid2)) {
      l = mid1;
    } else {
      r = mid2;
    }
  }
  cout << fixed << setprecision(10) << f(l);
  return 0;
}
