Envío 5797

Código

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

class Main
{
    public static void main(String[] args) throws IOException{
        List<Integer> arr = new ArrayList<Integer>();
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st;
        st = new StringTokenizer(br.readLine());
        st = new StringTokenizer(br.readLine());
        int res = 0;
        int clave = 0;
        while(st.hasMoreTokens()){
            arr.add(Integer.parseInt(st.nextToken()));
        }
        
        for(int i=arr.size()-1;i>=0;i--){
            res+=arr.get(i);
                if(res<0){
                    clave=i;
                }
        }
        if(clave == 0){
            System.out.println("Impossible");        
        }else{
            System.out.println(clave);
        }
    }
}