#include <bits/stdc++.h>
using namespace std;
int n;
double a[200010], l, r, ml, mr;
void nhap() {
  cin >> n;
  for (int i = 1; i <= n; ++i) cin >> a[i];
}
double func(double x) {
  double ma = 0, mi = 0, sum = 0;
  for (int i = 1; i <= n; ++i) {
    sum += a[i] - x;
    ma = max(ma, sum);
    mi = min(mi, sum);
  }
  return abs(ma - mi);
}
int main() {
  nhap();
  l = -20000, r = 20000;
  for (int i = 1; i <= 100; ++i) {
    ml = (l + l + r) / 3;
    mr = (r + r + l) / 3;
    if (func(ml) > func(mr))
      l = ml;
    else
      r = mr;
  }
  printf("%.10f", func(l));
  return 0;
}
