求大神指教哪里错了

#include <stdio.h>
int main() 
{ 
    /* 定义需要计算的日期 */
    int year = 2008;
    int month = 8;
    int day = 8;
    int a = 30;
    int b = 31;
    int sum , f;
    switch(month)
    {
        case 1:sum=0;
        break;
        case 2:sum=b;
        break;
        case 3:sum=a+b;
        brake;
        case 4:sum=a+2*b;
        break;
        case 5:sum=2*a+2*b;
        break;
        case 6:sum=2*a+3*b;
        break;
        case 7:sum=3*a+3*b;
        break;
        case 8:sum=3*a+4*b;
        break;
        case 9:sum=3*a+5*b;
        break;
        case 10:sum=4*a+5*b;
        break;
        case 11:sum=4*a+6*b;
        break;
        case 12:sum=5*a+6*b;
        break;
        default;
        printf("一年只有12个月哦~");
        break:
    }
    if(year%4==0&&year%100!=0||year%400==0)
        f=1;
    else
        f=2;
    if(month>2)
        sum=sum+day-f;
    else
        sum+=day;
    printf("%d年%d月%d日是该年的第%d天。",year,month,day,sum);
	return 0;
}