divisible by 3(accepted)

#include<stdio.h>
int found(int a)
{
int res=a/3;
res=res*2;

   if(a%3==2)
        {
            return res+1;

        }
    else
        {
            return res;
        }
}


int main(void)
{


int a,b,cases,caseno=0;
scanf("%d",&cases);
while(cases--)
{
scanf("%d %d",&a,&b);

 printf("Case %d: %d\n",++caseno,found(b)-found(a-1));
}
return 0;

return 0;
}