Envío 3161

Código

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {

    public static void main(String[] args) throws Throwable {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st;
        for(String ln; (ln=in.readLine())!=null;) {
            int N = Integer.parseInt(ln);
            st = new StringTokenizer(in.readLine());
            int[] values = new int[N];
            for(int i=0;i<N;i++) values[i] = Integer.parseInt(st.nextToken());
            int[] left = new int[N];
            int[] right = new int[N];
            left[0] = values[0];
            right[N-1] = values[N-1];
            for(int i =1, j=N-1; i<N;i++,j--) {
                left[i] = left[i-1] + values[i];
                right[j-1] = right[j] + values[j-1];
            }

            for(int i =0; i+1<N;i++)
                if(left[i]>0 && right[i+1]<0) {
                    System.out.println(i + 1);
                    return;
                }
            System.out.println("Impossible");
        }
    }
}