#include"stdio.h"
#define PASSWORD "123456"

int verify_password (char *password)
{
	int authenticated;
	char buffer[8];
	authenticated=strcmp(password,PASSWORD);
	strcpy(buffer,password);
	return authenticated;
}
main()
{
	int valid_flag=0;
	char password[1024];
	while(1)
	{
		printf("please input password:  ");
		scanf("%s",password);
		valid_flag=verify_password(password);
		if(valid_flag)
		{
			printf("incorrect password！\n");
		}
		else
		{
			printf("congratulation!\n");
			break;
		} 
	}
}