#include <bits/stdc++.h>
using namespace std;
vector<double> v;
int n;
double f(double x) {
  double mine = 0, mini = 0, maxi = 0;
  for (int i = 0; i < n; ++i) {
    mine += v[i] - x;
    mini = min(mini, mine);
    maxi = max(maxi, mine);
  }
  return abs(maxi - mini);
}
int main() {
  scanf("%d", &n);
  v.resize(n);
  for (int i = 0; i < n; ++i) scanf("%lf", &v[i]);
  int cnt = 0;
  double l = -1e5 + 100, r = 1e5 + 100;
  while (cnt < 300) {
    double left = (r + 2 * l) / 3;
    double right = (2 * r + l) / 3;
    if (f(left) < f(right))
      r = right;
    else
      l = left;
    ++cnt;
  }
  printf("%.10f\n", f(l));
  return 0;
}
