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;
template <typename T1, typename T2>
std::istream& operator>>(std::istream& in, pair<T1, T2>& a) {
  in >> a.first >> a.second;
  return in;
}
template <typename T1, typename T2>
std::ostream& operator<<(std::ostream& out, pair<T1, T2>& a) {
  out << a.first << " " << a.second;
  return out;
}
const long long N = 2e5 + 5;
long long a[N];
double b[N];
long long n;
double calc(double x) {
  for (long long i = 0; i < n; i++) b[i + 1] = a[i] - x;
  double s = 0, ans = 0;
  b[0] = 0;
  for (long long i = 1; i < n + 1; i++) {
    b[i] += b[i - 1];
  }
  double l = 0, u = 0;
  for (long long i = 1; i < n + 1; i++) {
    ans = max(ans, abs(b[i] - l));
    ans = max(ans, abs(b[i] - u));
    l = min(l, b[i]);
    u = max(u, b[i]);
  }
  return ans;
}
void solve() {
  cin >> n;
  for (long long i = 0; i < n; i++) cin >> a[i];
  double L = -10002, U = 10002;
  for (long long i = 0; i < 90; i++) {
    double d = (U - L) / 3;
    if (calc(L + d) > calc(L + 2 * d)) {
      L = L + d;
    } else {
      U = U - d;
    }
  }
  cout << calc(L);
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cout << setprecision(9);
  cout << fixed;
  long long t = 1;
  while (t--) solve();
  return 0;
}
