C programming: Leap year

#include <stdio.h>
#include <stdlib.h>
 
int main(){
    int a;
    printf("Please enter a year: \n");
    scanf("%d,", &a);
 
    if(a%4==0 && a%100!=0){
        printf("You entered %d and this is a leap year. \n", a);
    }
    else if (a%100==0 && a%400==0){
        printf("You entered %d and this is a leap year. \n", a);
    }
    else{
        printf("You entered %d and this is NOT a leap year. \n", a);
    }
 
    return 0;
 
}