#include <stdio.h>
main() 
{ 
	unsigned int day,month,year,sum,leap; 
	printf("\n please input year,month,day\n"); 
	scanf("%d,%d,%d",&year,&month,&day); 
	switch(month) 
	{	case 1:sum=0;
			break; 
		case 2:sum=31;
			break;
		case 3:sum=59;
			break; 
		case 4:sum=90;
			break;
		case 5:sum=120;
			break; 
		case 6:sum=151;
			break; 
		case 7:sum=181;
			break; 
		case 8:sum=212;
			break; 
		case 9:sum=243;
			break; 
		case 10:sum=273;
			break; 
		case 11:sum=304;
			break;
		case 12:sum=334;
			break; 
		default:printf("data error");
			break; } 
	sum=sum+day--;  //mutated statement
	if(year%400==0||(year%4==0&&year%100!=0))
		leap=1; 
	else 
		leap=0; 
	if(leap==1&&month>2)
		sum++; 
	printf("It is the %d th day.",sum);
}