import java.util.*;
import java.io.*;
import java.math.*;

/**
 * Auto-generated code below aims at helping you parse
 * the standard input according to the problem statement.
 **/
class Solution {

    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        int result=1000;
        int aux1, in2, aux2;
        int n = in.nextInt(); // the number of temperatures to analyse
        in.nextLine();
        String temps = in.nextLine(); // the n temperatures expressed as integers ranging from -273 to 5526
        String [] temp = temps.split(" ");
        if(n==0){
            result=0;
        }
        for(int i=0; i<n;i++){
            result =result;
            aux1=-result;
            in2=Integer.parseInt(temp[i]);
            aux2=-in2;
            if(in2>0){
                if(result>0){
                    if(result>in2){
                        result=in2;
                    }
                }else{
                    if(aux1>=in2){
                        result=in2;
                    }
                }
            }else{

                if(result>0){
                    if(result>aux2){
                        result=in2;
                    }
                }else{
                    if(aux1>aux2){
                        result=in2;
                    }
                }
            }
        }
        // Write an action using System.out.println()
        // To debug: System.err.println("Debug messages...");

        System.out.println(result);
    }
}