def main():
    print('==Exercise 3==')
    
    flag=True
    while flag:
        a = input("pls input a number:")
        try: 
            a = int(a)
            flag=False
        except :
            print("pls input a number!")
    
    print(f"Test if the number {a} is even: {True if a%2==0 else False}")

    #我其实挺想直接a%2==0的，不过尊重一下本节课的主题
    
    print('==End Of Ex3==')
    return 0

if __name__ == '__main__':
    main()