def succ(xpos, ypos, orientation):
    successors = []

    if orientation == 'N':
        successors.append(['LEFT', xpos, ypos, 'W'])
        successors.append(['RIGHT', xpos, ypos, 'E'])
        if ypos > 0:
            successors.append(['FORWARD', xpos, ypos - 50, 'N'])
    
    if orientation == 'S':
        successors.append(['LEFT', xpos, ypos, 'E'])
        successors.append(['RIGHT', xpos, ypos, 'W'])
        if ypos < 750:
            successors.append(['FORWARD', xpos, ypos + 50, 'S'])

    if orientation == 'W':
        successors.append(['LEFT', xpos, ypos, 'S'])
        successors.append(['RIGHT', xpos, ypos, 'N'])
        if xpos > 0:
            successors.append(['FORWARD', xpos - 50, ypos, 'W'])

    if orientation == 'E':
        successors.append(['LEFT',xpos, ypos, 'N'])
        successors.append(['RIGHT', xpos, ypos, 'S'])
        if xpos < 750:
            successors.append(['FORWARD', xpos + 50, ypos, 'E'])

    return successors