PRIME1 WA....

#include<stdio.h>
#include<math.h>
int isprime(unsigned long x)
{
    int i,c=0;
    if(x==1)
        return 0;
    else if(x==2 || x==3)
        return 1;
    else if(x%2==0)
        return 0;
    else if(x%3==0)
        return 0;
    else
    {
        for(i=5;(i<=sqrt(x))&&((i%3)!=0);i+=2)
        {
            if(x%i==0)
            c++;
        }
        if(c==0)
           return 1;
        else
           return 0;
    }
}

int main()
{
    int t,i,j;
    unsigned long a,b;
    scanf("%d",&t);
    while(t--)
    {
        scanf("%lu%lu",&a,&b);
        for(i=a;i<=b;i++)
        {
            if(isprime(i)==1)
                printf("%lu\n",i);
        }
        printf("\n");
   }
   return 0;
}