def assemble_transformation(ops: list[list[str]], i: int, j: int) -> list[str]:
    if i == 0 and j == 0:
        return []
    else:
        if ops[i][j][0] == "C" or ops[i][j][0] == "R":
            seq = assemble_transformation(ops, i - 1, j - 1)
            seq.append(ops[i][j])
            return seq
        elif ops[i][j][0] == "D":
            seq = assemble_transformation(ops, i - 1, j)
            seq.append(ops[i][j])
            return seq
        else:
            seq = assemble_transformation(ops, i, j - 1)
            seq.append(ops[i][j])
            return seq