from Bio import SeqIO

def multiple_lcs_length(input):
    fasta_sequences = SeqIO.parse(open(input), 'fasta')
    first = str(next(fasta_sequences).seq)
    second = str(next(fasta_sequences).seq)
    third = str(next(fasta_sequences).seq)
    matr = [[[]]]
    for i in range(len(first) + 1):
        matr[0][0].append("")

    for i in range(1, len(second) + 1):
        matr[0].append([""])
        for _ in range(len(first)):
            matr[0][i].append("")

    for i in range(1, len(third)):
        matr.append([[""]])
        for _ in range(len(first)):
            matr[i][0].append("")


    print(matr)

    for x in range(1, len(third) + 1):
        for y in range(1, len(second) + 1):
            tmpy = [[]]
            for z in range(1, len(first) + 1):
                count = len(matr[x-1][y-1][z-1])
                if first[z-1] == second[y-1] and second[y-1] == third[x-1]:
                    count += 1
                if len(matr[x-1][y][z]) > count:
                    count = len(matr[x-1][y][z])
                    tmp = matr[x-1][y][z]

                if len(matr[x][y-1][z]) > count:
                    count = len(matr[x][y-1][z])
                    tmp = matr[x][y-1][z]
                if len(matr[x][y][z-1] > count) :
                    tmp = matr[x - 1][y - 1][z - 1]
                    if first[z-1] == second[y-1] and second[y-1] == third[x-1]:
                        tmp += first[z-1]

                tmpy.append(tmp)
                print("yes")
            matr.append(tmpy)

    return matr[-1][-1][-1]

print(multiple_lcs_length('data012.fna'))