#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
int n;
vector<double> v;
double func(double x) {
  double sum = (v[0] - x);
  int now;
  if ((v[0] - x) < 0)
    now = -1;
  else
    now = 1;
  vector<double> a1;
  vector<double> a2;
  for (int i = 1; i < n; i++) {
    if (v[i] - x <= 0) {
      if (now == -1)
        sum += (v[i] - x);
      else {
        now = -1;
        a1.push_back(sum);
        a2.push_back(-sum);
        sum = v[i] - x;
      }
    } else {
      if (now == 1)
        sum += (v[i] - x);
      else {
        a1.push_back(sum);
        a2.push_back(-sum);
        now = 1;
        sum = v[i] - x;
      }
    }
  }
  a1.push_back(sum);
  a2.push_back(-sum);
  double ans = 0;
  sum = 0;
  for (int i = 0; i < a1.size(); i++) {
    sum += a1[i];
    ans = max(sum, ans);
    if (sum < 0) sum = 0;
  }
  sum = 0;
  for (int i = 0; i < a2.size(); i++) {
    sum += a2[i];
    ans = max(ans, sum);
    if (sum < 0) sum = 0;
  }
  return ans;
}
void solve() {
  cin >> n;
  v = vector<double>(n);
  for (int i = 0; i < n; i++) cin >> v[i];
  double lo = -1e4 - 10;
  double hi = 1e4 + 10;
  int cnt = 0;
  while (true) {
    double m1 = lo + (hi - lo) / 3;
    double m2 = hi - (hi - lo) / 3;
    double f1 = func(m1);
    double f2 = func(m2);
    if (f1 > f2) {
      lo = m1;
    } else
      hi = m2;
    cnt++;
    if (cnt == 100) break;
  }
  printf("%0.9f\n", func(lo));
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int tests = 1;
  while (tests--) {
    solve();
  }
}
