Leap year problem from UVa in C language

 Leap year problem from UVa in C language. Find which year is leap year.

 

#include <stdio.h>

int main()

{

    int long yr, flag=0;

    while(scanf("%ld", &yr) != EOF){

        printf("\n");

        if(yr%4==0 && yr%100!=0){

            printf("This is leap year.\n");

            flag=1;

        }

        else if(yr%400==0){

            printf("This is leap year.\n");

            flag=1;

        }

        if(yr%15==0){

            printf("This is huluculu festival year.\n");

            flag=1;

        }

        if(yr%55==0){

            printf("This is bulukulu festival year.\n");

            flag=1;

        }

        if(flag==0)

            printf("This is an ordinary year.\n");

        flag=0;

    }

    return 0;

}