def path(T,s,current):
    return find_path(T,s,current,0)

def find_path(T,s,current,count):

    for element in T:

        if element[1] == current:

            if element[0] == s:
                return count + 1

            else:
                return find_path(T,s,element[0],count + 1)

    return -1

def check_connection_k(T,s,d,k):
    numero_salti = path(T,s,d)

    if numero_salti == -1:
        return False

    if numero_salti <= k:
        return True

    return False


T = [[0,1],[1,3],[3,6],[6,8],[8,10]]

print(check_connection_k(T,0,10,5))