请问大佬哪里不对？

#include <stdio.h>

int main() 

{ 

    int year = 2008;

    int month = 8;

    int day = 8;

    int sum;  

    switch(month)

    {

        case(1):sum=day;break;

        case(2):sum=day+31;break;

        case(3):sum=day+31+28;break;

        case(4):sum=day+31+28+31;break;

        case(5):sum=day+31+28+31+30;break;

        case(6):sum=day+31+28+31+30+31;break;

        case(7):sum=day+31+28+31+30+31+30;break;

        case(8):sum=day+31+28+31+30+31+30+31;break;

        case(9):sum=day+31+28+31+30+31+30+31+31;break;

    }

    if(year%4==0&&year%100!=0||year%400==0)

    {

        sum+=1;

    }

    else

    {

        sum=sum+0;

    }

    printf("是该年的第%d天"，sum);

    return 0;

}