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 double PI = acos(-1);
const double eps = 1e-9;
const int inf = 2000000000;
const long long infLL = 9000000000000000000;
inline bool checkBit(long long n, int i) { return n & (1LL << i); }
inline long long setBit(long long n, int i) {
  return n | (1LL << i);
  ;
}
inline long long resetBit(long long n, int i) { return n & (~(1LL << i)); }
int dx[] = {0, 0, +1, -1};
int dy[] = {+1, -1, 0, 0};
inline bool EQ(double a, double b) { return fabs(a - b) < 1e-9; }
inline bool isLeapYear(long long year) {
  return (year % 400 == 0) || (year % 4 == 0 && year % 100 != 0);
}
inline void normal(long long &a) {
  a %= 1000000007;
  (a < 0) && (a += 1000000007);
}
inline long long modMul(long long a, long long b) {
  a %= 1000000007, b %= 1000000007;
  normal(a), normal(b);
  return (a * b) % 1000000007;
}
inline long long modAdd(long long a, long long b) {
  a %= 1000000007, b %= 1000000007;
  normal(a), normal(b);
  return (a + b) % 1000000007;
}
inline long long modSub(long long a, long long b) {
  a %= 1000000007, b %= 1000000007;
  normal(a), normal(b);
  a -= b;
  normal(a);
  return a;
}
inline long long modPow(long long b, long long p) {
  long long r = 1;
  while (p) {
    if (p & 1) r = modMul(r, b);
    b = modMul(b, b);
    p >>= 1;
  }
  return r;
}
inline long long modInverse(long long a) { return modPow(a, 1000000007 - 2); }
inline long long modDiv(long long a, long long b) {
  return modMul(a, modInverse(b));
}
const int MX = 201000;
double a[MX], x[MX];
int n;
double func(double val) {
  for (int i = 0; i < n; ++i) x[i] = a[i] - val;
  double maxval = -inf, tempval = 0;
  for (int i = 0; i < n; ++i) {
    tempval += x[i];
    maxval = max(maxval, tempval);
    if (tempval < 0) tempval = 0;
  }
  tempval = 0;
  for (int i = 0; i < n; ++i) {
    tempval += x[i];
    maxval = max(maxval, abs(tempval));
    if (tempval > 0) tempval = 0;
  }
  return maxval;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  cout.unsetf(ios::floatfield);
  cout.precision(10);
  cout.setf(ios::fixed, ios::floatfield);
  ;
  cin >> n;
  for (int i = 0; i < n; ++i) cin >> a[i];
  double low = -MX, high = MX;
  while (!EQ(low, high)) {
    double fm = (low + low + high) / 3;
    double sm = (low + high + high) / 3;
    if (func(fm) < func(sm))
      high = sm;
    else
      low = fm;
    ;
  }
  cout << func(low) << '\n';
  return 0;
}
