这个第一题为什么不对啊，怎么用c写啊

我的代码
#include <stdio.h>
int main()
{
double m,n;
printf("please tap your Height and weight\n");
scanf("lf% lf%",&m,&n);
double k=n/（m*m）;

if(k<18.50)
printf("guoqing\n");
if(18.50<=k&&k<=24.00)
printf("zhengchang\n");
if(24.00<k&&k<=30.00)
printf("chaozhong\n");
if(k>30.00)
printf("feipang\n");

return 0;
}

scanf("%lf%lf", &m, &n);