判断是否为闰年，为啥下面的代码不对啊

#include<stdio.h>
int main()
{
int a;
printf("Input a year:");
scanf("%d",&a);
if(a%4==0&&a%100!=0)
{
printf("%d is leap year",a);
}
else if(a%400==0)
{
printf("%d is leap year",a);
}
else
{printf("%d is not leap year",a);}
return 0;

}

逻辑没问题啊，能看看错误提示吗