百练 2723 不吉利日期

题目链接：http://bailian.openjudge.cn/practice/2723

#include<stdio.h>
int main()
{
	int day[13]={0,12,31,28,31,30,31,30,31,31,30,31,30};
	int w;
	int i;
	scanf("%d",&w);
	for(i=1;i<=12;i++)
	{w=(w+day[i])%7;
	if(w==5) printf("%d\n",i);
	}
	return 0;

}