习题1-7

#include<stdio.h>
int main() {
    int year;
    scanf("%d", &year);
    if (year%100==0) {
        if (year%400==0)
        {
            printf("yes");
        }
        else
        {
            printf("no");
        }
    }
    else{
        if (year%4==0)
        {
            printf("yes");
        }
        else
        {
            printf("no");
        }
    }
    return 0;
}