#include<stdio.h>

int main(void)
{
         int years, m, day;
         scanf("%d %d\n", &years, &m);
         if(years%400 == 0 || (years%4 == 0 && years%400 !=0));
         {
                if(m == 2)    {
                               printf("day=29");
                              }
                else {
                              if(m ==4 || m == 6 || m==9 ||m==11);
                              {
                               printf("day=30");
                              }  
                else          {
                              printf("day=31");
                              }
                     }
         }
         else
         {
                if(m == 2)    {
                               printf("day=28");
                              }
                else {
                              if(m ==4||m==6||m==9||m ==11);
                              {                  
                               printf("day=30");
                              }  
                else          {
                              printf("day=31");
                              }
                     }

         }
         return 0;
}


报错说的是else 前面没有if；求各位大侠帮帮忙，题目是：
输入年份和月份判断这个月份的天数。

多谢各位大侠！！！感激涕零！！！