from itertools import (chain)


# kronecker :: [[a]] -> [[a]] -> [[a]]
def kronecker(m1, m2):
    return concatMap(
        lambda row2: concatMap(
            lambda elem2: [concatMap(
                lambda num2: concatMap(
                    lambda num1: [num1 * num2],
                    elem2
                ),
                m1[row2]
            )],
            m2
        ),
        range(len(m2))
    )


# concatMap :: (a -> [b]) -> [a] -> [b]
def concatMap(f, xs):
    return list(
        chain.from_iterable(
            map(f, xs)
        )
    )


if __name__ == '__main__':
    # Sample 1
    r = [[1, 2], [3, 4]]
    s = [[0, 5], [6, 7]]

    # Sample 2
    t = [[0, 1, 0], [1, 1, 1], [0, 1, 0]]
    u = [[1, 1, 1, 1], [1, 0, 0, 1], [1, 1, 1, 1]]

    # Result 1:
    for row in kronecker(r, s):
        print(row)
    print()

    # Result 2
    for row in kronecker(t, u):
        print(row)