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.*;
import java.util.StringTokenizer;

import static java.lang.Integer.*;
import static java.lang.Math.*;

public class C {
	public static void main(String[] args) throws Throwable{
		BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st=new StringTokenizer(in.readLine());
		int N=parseInt(st.nextToken());
		st=new StringTokenizer(in.readLine());
		double[] arr=new double[N];
		double sum=0;
		for(int i=0;i<N;i++)
			sum+=(arr[i]=parseInt(st.nextToken()));
		sum/=N;
		for(int i=0;i<N;i++)
			arr[i]-=sum;
		System.out.println(sum(arr));
	}
	static double sum(double[] arr) {
		double act=0,r=0;
		for (double v:arr) {act+=v; if (act>r) r=act; if (act<0) act=0;}
		return r;
	}
}
