输入2020为什么输出却是20(语言-c语言)

Question

#include<stdio.h>
int main()
{
int a;
scanf("%d",&a);
if((a%400==0)||(a%4==0)&&(a%100!=0))
printf("%d is a leap year with an even numbers.");
else
printf("No");
}
为什么在输入2020后的结果是20 is a leap year with an even numbers.

Answer 1

第七行改为：
printf("%d is a leap year with an even numbers.",a);