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

import java.io.IOException;
import java.io.InputStream;
import java.util.NoSuchElementException;

public class Main {
	private final double EPS = 1e-10;

	public void solve() {
		FastScanner scanner = new FastScanner();
		int N = scanner.nextInt();
		double[] a = new double[N];
		for (int i = 0; i < N; i++) {
			a[i] = scanner.nextInt();
		}
		double low = -100010.0, high = 100010.0;
		while (high - low > EPS) {
			double mid = (high + low) / 2.0;
			double maximum = Integer.MIN_VALUE;
			double minimum = Integer.MAX_VALUE;

			double sum = 0.0;
			for (int i = 0; i < N; i++) {
				if (i == 0 || (a[i - 1] - mid) * (a[i] - mid) > 0.0) {
					sum += (a[i] - mid);
				} else {
					sum = (a[i] - mid);
				}
				maximum = Math.max(maximum, sum);
				minimum = Math.min(minimum, sum);
			}
			if (maximum + minimum > 0) {
				low = mid;
			} else {
				high = mid;
			}

		}
		double maximum = Integer.MIN_VALUE;
		double minimum = Integer.MAX_VALUE;

		double sum = 0.0;
		for (int i = 0; i < N; i++) {
			if (i == 0 || (a[i - 1] - high) * (a[i] - high) > 0.0) {
				sum += (a[i] - high);
			} else {
				sum = (a[i] - high);
			}
			maximum = Math.max(maximum, sum);
			minimum = Math.min(minimum, sum);
		}

		System.out.println(Math.min(maximum, Math.abs(minimum)));

	}

	public static void main(String[] args) {
		new Main().solve();
	}
}

class FastScanner {
	private final InputStream in = System.in;
	private final byte[] buffer = new byte[1024];
	private int ptr = 0;
	private int buflen = 0;

	private boolean hasNextByte() {
		if (ptr < buflen) {
			return true;
		} else {
			ptr = 0;
			try {
				buflen = in.read(buffer);
			} catch (IOException e) {
				e.printStackTrace();
			}
			if (buflen <= 0) {
				return false;
			}
		}
		return true;
	}

	private int readByte() {
		if (hasNextByte())
			return buffer[ptr++];
		else
			return -1;
	}

	private static boolean isPrintableChar(int c) {
		return 33 <= c && c <= 126;
	}

	private void skipUnprintable() {
		while (hasNextByte() && !isPrintableChar(buffer[ptr]))
			ptr++;
	}

	public boolean hasNext() {
		skipUnprintable();
		return hasNextByte();
	}

	public String next() {
		if (!hasNext())
			throw new NoSuchElementException();
		StringBuilder sb = new StringBuilder();
		int b = readByte();
		while (isPrintableChar(b)) {
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}

	public int nextInt() {
		return (int) nextLong();
	}

	public long nextLong() {
		if (!hasNext())
			throw new NoSuchElementException();
		long n = 0;
		boolean minus = false;
		int b = readByte();
		if (b == '-') {
			minus = true;
			b = readByte();
		}
		if (b < '0' || '9' < b) {
			throw new NumberFormatException();
		}
		while (true) {
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			} else if (b == -1 || !isPrintableChar(b)) {
				return minus ? -n : n;
			} else {
				throw new NumberFormatException();
			}
			b = readByte();
		}
	}
}