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;
const int dr[] = {1, 0, -1, 0, 1, 1, -1, -1};
const int dc[] = {0, 1, 0, -1, 1, -1, -1, 1};
const double eps = 1e-9;
const int INF = 0x7FFFFFFF;
const long long INFLL = 0x7FFFFFFFFFFFFFFFLL;
const double pi = acos(-1);
template <class T>
T take(queue<T> &O) {
  T tmp = O.front();
  O.pop();
  return tmp;
}
template <class T>
T take(stack<T> &O) {
  T tmp = O.top();
  O.pop();
  return tmp;
}
template <class T>
T take(priority_queue<T> &O) {
  T tmp = O.top();
  O.pop();
  return tmp;
}
template <class T>
inline void getint(T &num) {
  bool neg = 0;
  num = 0;
  char c;
  while ((c = getchar_unlocked()) && (!isdigit(c) && c != '-'))
    ;
  if (c == '-') {
    neg = 1;
    c = getchar_unlocked();
  }
  do num = num * 10 + c - '0';
  while ((c = getchar_unlocked()) && isdigit(c));
  if (neg) num = -num;
}
template <class T>
inline bool inRange(T z, T a, T b) {
  return a <= z && z <= b;
}
void OPEN(string in = "input.txt", string out = "output.txt") {
  freopen(in.c_str(), "r", stdin);
  freopen(out.c_str(), "w", stdout);
  return;
}
int arr[200005];
int n;
vector<int> vc;
inline double cek(double x) {
  double tmp = 0.0, ansz = 0.0;
  for (int(i) = (0), _t = (n); i < (_t); ++(i)) {
    tmp = max(tmp + arr[i] - x, 0.0);
    ansz = max(ansz, tmp);
  }
  tmp = 0.0;
  for (int(i) = (0), _t = (n); i < (_t); ++(i)) {
    tmp = max(tmp + -(arr[i] - x), 0.0);
    ansz = max(ansz, tmp);
  }
  return ansz;
}
int main(int argc, const char *argv[]) {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cin >> n;
  for (int(i) = (0), _t = (n); i < (_t); ++(i)) cin >> arr[i];
  double lo = -10000.0, hi = 10000.0, le, ri;
  for (int(i) = (0), _t = (120); i < (_t); ++(i)) {
    le = lo + (hi - lo) / 3.;
    ri = lo + (hi - lo) * 2. / 3.;
    double cle = cek(le), cri = cek(ri);
    if (cle < cri)
      hi = ri;
    else if (cle > cri)
      lo = le;
    else {
      lo = le;
      hi = ri;
    }
  }
  cout << fixed << setprecision(10) << cek(lo) << "\n";
  return 0;
}
