c 语言 哪里错了啊

#include <stdio.h>
void main()
{
int rui(int x);
int a[13]={0,31,28,31,30,31,30,31,31,30,31,30,31} ;
int i, leap=0,year,month,day,days=0;

do
{
scanf("%d%d%d",&year,&month,&day);
if(month>0 &&month<=12&&day>0&&day<=a[month])
leap=1;
else
leap=0;
} while (leap==0);
for(i=0;i<month;i++) days+=a[i];
if (rui (year)&&month>2 ) days++;
printf("此日期是次年中的弟%d天",days );
}
int rui(int x)
{int z;
if ((z%400==0)||(z%4==0&&z%100!=0)) z=1;
else z=0;
return (z);
}

//do while
//while写后面，要加分号