Problem: You are given a sequence of n integers a1, a2, ..., an. 

Determine a real number x such that the weakness of the sequence a1 - x, a2 - x, ..., an - x is as small as possible.

The weakness of a sequence is defined as the maximum value of the poorness over all segments (contiguous subsequences) of a sequence.

The poorness of a segment is defined as the absolute value of sum of the elements of segment.

Input

The first line contains one integer n (1 ≤ n ≤ 200 000), the length of a sequence.

The second line contains n integers a1, a2, ..., an (|ai| ≤ 10 000).

Output

Output a real number denoting the minimum possible weakness of a1 - x, a2 - x, ..., an - x. Your answer will be considered correct if its relative or absolute error doesn't exceed 10 - 6.

Examples

Input

3
1 2 3


Output

1.000000000000000


Input

4
1 2 3 4


Output

2.000000000000000


Input

10
1 10 2 9 3 8 4 7 5 6


Output

4.500000000000000

Note

For the first case, the optimal value of x is 2 so the sequence becomes  - 1, 0, 1 and the max poorness occurs at the segment "-1" or segment "1". The poorness value (answer) equals to 1 in this case. 

For the second sample the optimal value of x is 2.5 so the sequence becomes  - 1.5, - 0.5, 0.5, 1.5 and the max poorness occurs on segment "-1.5 -0.5" or "0.5 1.5". The poorness value (answer) equals to 2 in this case.

Solution (in CPP):

Solution:
#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
;
long long max(long long a, long long b) {
  if (a > b)
    return a;
  else
    return b;
}
long long min(long long a, long long b) {
  if (a > b)
    return b;
  else
    return a;
}
long long gcd(long long a, long long b) { return (b == 0) ? a : gcd(b, a % b); }
inline long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }
inline long long normalize(long long x, long long mod) {
  x %= mod;
  if (x < 0) x += mod;
  return x;
}
long long dx[4] = {0, 0, 1, -1};
long long dy[4] = {1, -1, 0, 0};
string abc = "abcdefghijklmnopqrstuvwxyz";
const double PI = acosl(-1);
const long long mod = 998244353;
const long long inf = 1e18 + 5;
inline long long add(long long a, long long b, long long p = mod) {
  long long c = a + b;
  if (c >= p) c -= p;
  return c;
}
inline long long sub(long long a, long long b, long long p = mod) {
  long long c = a - b;
  if (c < 0) c += p;
  return c;
}
inline long long mul(long long a, long long b, long long p = mod) {
  return (a * 1ll * b) % p;
}
long long floor1(long long n, long long k) {
  if (n % k == 0 || n >= 0) return n / k;
  return (n / k) - 1;
}
long long ceil1(long long n, long long k) { return floor1(n + k - 1, k); }
long long powm(long long a, long long b) {
  long long res = 1;
  while (b) {
    if (b & 1) res = (res * a) % mod;
    a = (a * a) % mod;
    b >>= 1;
  }
  return res;
}
const long long N = 2e5 + 5;
long long n, m, k;
long long a[N], b[N];
long double cache[N];
long double dp() {
  long double mx = 0.0;
  long double cur = 0.0;
  for (long long i = (1); i < (n + 1); ++i) {
    if (cur + cache[i] > cache[i])
      cur = cur + cache[i];
    else
      cur = cache[i];
    if (cur > mx) mx = cur;
  }
  return mx;
}
long double f(long double x) {
  long double ans = 0.0;
  for (long long i = (1); i < (n + 1); ++i) cache[i] = a[i] - x;
  ans = max(ans, dp());
  for (long long i = (1); i < (n + 1); ++i) cache[i] = -cache[i];
  ans = max(ans, dp());
  return ans;
}
long double ternary_search(long double l, long double r) {
  long double eps = 1e-12;
  while (r - l > eps) {
    long double m1 = l + (r - l) / 3.00;
    long double m2 = r - (r - l) / 3.00;
    long double f1 = f(m1);
    long double f2 = f(m2);
    if (f1 > f2)
      l = m1;
    else
      r = m2;
  }
  return f(l);
}
void solve() {
  cin >> n;
  for (long long i = (1); i < (n + 1); ++i) cin >> a[i];
  cout << ternary_search(-20005, 20005) << "\n";
}
signed main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cout << fixed << setprecision(10);
  long long t = 1;
  while (t--) {
    solve();
  }
  return 0;
}