Envío 874

Código

def cum_sum(arr):

    res = [0]

    for i in arr:
        res.append(res[-1] + i)

    return res

N = int(input())
arr = [int(x) for x in input().split()]
s_arr = cum_sum(arr)
sol = -1

for idx in range(N):

    first_half = s_arr[idx]
    second_half = s_arr[-1] - s_arr[idx]
    if first_half > 0 and second_half < 0:
        sol = idx
        break

if sol == -1:
    print("Impossible")
else:
    print(sol)