def can_take_courses(a,c, i, n):
    if i==len(c):
        x = sum(a)
        if x == n:
            print(a)
        return
    a.append(c[i])
    can_take_courses(a,c, i+1, n)
    a.pop()
    can_take_courses(a,c, i+1, n)

can_take_courses([], [1,2,3,4,5], 0, 5)