def ForwardTraverse(strand, startBase):
    """
    Traverse scaffold/staple strand forward by a single base.
    Returns next adjacent base and block.
    """

    currentBase = startBase
    currentBlock = strand[currentBase[0]][currentBase[1]]

    nextBase = [currentBlock[2], currentBlock[3]]
    nextBlock = strand[nextBase[0]][nextBase[1]]

    return nextBase, nextBlock