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 long long int MOD = 1000000007;
const long long int INF = LONG_LONG_MAX;
const vector<vector<long long int> > adj4({{0, 1}, {0, -1}, {1, 0}, {-1, 0}});
const vector<vector<long long int> > adj8(
    {{0, 1}, {0, -1}, {1, 0}, {-1, 0}, {-1, -1}, {1, -1}, {-1, 1}, {1, 1}});
long long int gcd(long long int a, long long int b) {
  return b == 0 ? a : gcd(b, a % b);
}
bool isprime(long long int n) {
  if (n == 2 || n == 3) return true;
  if (n < 2 || n % 2 == 0 || n % 3 == 0) return false;
  for (long long int i = 6; (i - 1) * (i - 1) <= n; i += 6) {
    if (n % (i - 1) == 0 || n % (i + 1) == 0) {
      return false;
    }
  }
  return true;
}
vector<bool> sprime;
void genPrime(long long int sz) {
  sprime = vector<bool>(sz, true);
  sprime[0] = false;
  sprime[1] = false;
  for (long long int i = (2); i < (sz); ++i) {
    if (sprime[i]) {
      for (long long int j = i * i; j < sz; j += i) {
        sprime[j] = false;
      }
    }
  }
}
long long int powMod(long long int a, long long int b, long long int mod) {
  long long int n = 1;
  long long int p = a;
  while (b > 0) {
    if (b % 2 == 1) {
      n *= p;
      n %= mod;
    }
    p *= p;
    p %= mod;
    b /= 2;
  }
  return n;
}
long long int modularInverse(long long int a, long long int mod) {
  return powMod(a, mod - 2, mod);
}
long long int bsfunction(long long int n) { return 0; }
long long int binarysearch(long long int left, long long int right,
                           long long int target) {
  if (left == right) {
    return left;
  }
  long long int mid =
      (left + right > 0) ? (left + right) / 2 : (left + right - 1) / 2;
  long long int val = bsfunction(mid);
  if (val > target) {
    return binarysearch(left, mid, target);
  } else if (val == target) {
    return mid;
  } else {
    return binarysearch(mid + 1, right, target);
  }
}
stringstream sss;
long long int n;
vector<long long int> arr;
double poor(double x) {
  double s = 0;
  double s2 = 0;
  double mx = 0;
  for (long long int i = 0; i < (n); ++i) {
    s = max(s + arr[i] - x, 0.0);
    s2 = max(s2 - arr[i] + x, 0.0);
    mx = max(mx, (max(s, s2)));
  }
  return mx;
}
void MAIN() {
  cin >> n;
  arr = vector<long long int>(n);
  for (long long int i = 0; i < (n); ++i) {
    cin >> arr[i];
  }
  double l = -10000, r = 10000;
  for (long long int t = 0; t < (200); ++t) {
    double m1 = l + (r - l) / 3;
    double r1 = poor(m1);
    double m2 = l + (r - l) * 2 / 3;
    double r2 = poor(m2);
    if (r1 > r2) {
      l = m1;
    } else {
      r = m2;
    }
  }
  cout << (poor(l)) << endl;
}
const long long int TESTCASEN = 1;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout << fixed << setprecision(10);
  sss << R"(
10
1 10 2 9 3 8 4 7 5 6
    )";
  for (long long int i = 0; i < (TESTCASEN); ++i) {
    MAIN();
  }
  return 0;
}
