def solution(l, t):
    for i in range(len(l)):
        for j in range(i, len(l)):
            if sum(l[i:j+1]) == t:
                return [i, j]
    return [-1, -1]

tests = [
        ([[1, 2, 3, 4], 15], [-1, -1]),
        ([[4, 3, 10, 2, 8], 12], [2, 3]),
        ]

for i, o in tests:
    result = solution(*i)
    print (i, result == o, result, o)