import sys
import array

# Writen by Attractive Chaos; distributed under the MIT license

# reference: http://www.syntagmatic.net/matrix-multiplication-in-python/

def matmul(a, b): # FIXME: no error checking
    ra, rb = list(range(len(a))), list(range(len(b)))
    c = [array.array('d', [b[j][i] for j in rb]) for i in rb]
    d = [array.array('d', [0 for j in range(len(b[0]))]) for i in ra] # transpose
    for i in ra:
        ai = a[i]
        for j in rb:
            d[i][j] = sum(ai[k] * c[j][k] for k in ra)
    return d