输出月份天数

#include <stdio.h>

void main()
{
	int year,month;
	scanf("%d%d",&year,&month);
	switch(month)
	{
	case 1:
	case 3:
	case 5:
	case 7:
	case 8:
	case 10:
	case 12:printf("31\n");break;
	case 2:
		{
			if((year % 4 == 0 && year % 100 != 0) || year % 400 == 0)
			   printf("29\n");
			else
				printf("28\n");
			break;
		}
	case 4:
	case 6:
	case 9:
	case 11:printf("30\n");break;
	default:printf("-1");break;
	}

}