Envío 3505

Código

import java.util.Scanner;
import java.util.Arrays;

class Main {
    private static final Scanner scanner = new Scanner(System.in);

    public static void main(String args[]) {
        int n = Integer.parseInt(scanner.nextLine()); // Number of elements in array
        long[] a = Arrays.stream(scanner.nextLine().split(" ")).map(Long::parseLong).mapToLong(x -> x).toArray(); // Array
        int result = split(a, n);

        System.out.println(result < 0 ? "Impossible" : result);
        scanner.close();
    }

    private static int split(long[] a, int n) {
        long right = Arrays.stream(a).sum();

        long left = 0;
        for (int i = 0; i < n; i++) {
            left += a[i];
            if (right - left < 0 && left > 0) {
                return i + 1;
            }
        }

        return -1;
    }
}