<求助>我想做个设定时间自动关机的小东西，怎么老是不对啊

# include<stdio.h>
# include<windows.h>
int main(void)
{
int m, n;
printf("请输入关机时间：\n");
scanf("%d",&m);
system("shutdown -s -t m");
printf("将在%d秒后关机，请输入验证取消关机！：________\b\b\b\b\b\b\b\b",m);
loop:
scanf("%d",&n);
if(n==123)
{
printf("取消自动关机！\n");
system("shutdown -a");
}
else if(n!=123)
{
printf("只有%d秒，快点啊！！！：\n________\b\b\b\b\b\b\b\b",m);
goto loop;
}
return 0;
}