Envío 775

Código

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

public class Main {

    public static void main(String[] args) throws Exception {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        for (String ln; (ln = in.readLine()) != null; ) {
            int N = Integer.parseInt(ln);
            int[] arr = new int[N];
            StringTokenizer st = new StringTokenizer(in.readLine());
            for (int i = 0; i < N; ++i) {
                arr[i] = Integer.parseInt(st.nextToken());
                if (i > 0) {
                    arr[i] += arr[i - 1];
                }
            }
            StringBuilder sb = new StringBuilder();
            for (int i = 1; i < N; ++i) {
                if(arr[i-1] > 0 && arr[N-1] - arr[i-1] < 0){
                    sb.append(i).append("\n");
                    break;
                }
            }
            if(sb.length() == 0)
                sb.append("Impossible\n");
            System.out.print(new String(sb));
        }

    }
}