判断素数的方法（Python版本）

    n = int(input())
    if n > 2:
    for i in range(2, int(n/2)):
        if n % i == 0:
            print('N')
            break
    else:
        print('Y')
    elif n == 2:
    print('Y')
    elif n == 1:
    print('N')
    elif n == 0:
    print('N')