def memoizedWalkCount(feet):
    table = [None] * (feet+1)
    def walkCount(ft):
        if table[ft] == None:
            if ft == 0:
                table[ft] = 1
            elif ft == 1:
                table[ft] = 1
            else:
                table[ft] = walkCount(ft-1) + walkCount(ft-2)
        return table[ft]
    return walkCount(feet)