#include <bits/stdc++.h>

using db = long double;

auto main() -> int {
  std::cin.tie(nullptr)->sync_with_stdio(false);

  int n;
  std::cin >> n;
  std::vector<int> a(n);
  int64_t sum = 0;
  for (auto &i : a) {
    std::cin >> i;
    sum += i;
  }
  db avg = 1.0l * sum / n;
  int li = 0, ri = 0;
  for (int i = 0; i < n - 1; ++i) {
    if (a[i] <= avg && avg <= a[i + 1]) {
      if (avg - a[i] <= a[i + 1] - avg) {
        li = ri = i;
      } else {
        li = ri = i + 1;
      }
    }
  }
  db l = std::min<db>(avg, a[li]), r = std::max<db>(avg, a[li]);
  db csum = a[li];
  for (int i = 0; i < n - 1; ++i) {
    if (li == 0) {
      csum += a[ri + 1];
      ++ri;
      l = std::min(l, csum / (i + 2));
      r = std::max(r, csum / (i + 2));
    } else if (ri == n - 1) {
      csum += a[li - 1];
      --li;
      l = std::min(l, csum / (i + 2));
      r = std::max(r, csum / (i + 2));
    } else {
      db avg1 = (csum + a[li - 1]) / (i + 2);
      db avg2 = (csum + a[ri + 1]) / (i + 2);
      if (l <= avg1 && avg1 <= r) {
        csum += a[li - 1];
        --li;
      } else if (l <= avg2 && avg2 <= r) {
        csum += a[ri + 1];
        ++ri;
      } else if (l - avg1 <= avg2 - r) {
        csum += a[li - 1];
        --li;
        l = avg1;
      } else {
        csum += a[ri + 1];
        ++ri;
        r = avg2;
      }
    }
  }
  std::cout << std::fixed << std::setprecision(10) << r - l << '\n';
}