Problem:
Score : 400 points

Problem Statement

We say that a odd number N is similar to 2017 when both N and (N+1)/2 are prime.

You are given Q queries.

In the i-th query, given two odd numbers l_i and r_i, find the number of odd numbers x similar to 2017 such that l_i ≤ x ≤ r_i.

Constraints

1≤Q≤10^5

1≤l_i≤r_i≤10^5

l_i and r_i are odd.

All input values are integers.

Input

Input is given from Standard Input in the following format:

Q
l_1 r_1
:
l_Q r_Q

Output

Print Q lines. The i-th line (1≤i≤Q) should contain the response to the i-th query.

Sample Input 1

1
3 7

Sample Output 1

2

3 is similar to 2017, since both 3 and (3+1)/2=2 are prime.

5 is similar to 2017, since both 5 and (5+1)/2=3 are prime.

7 is not similar to 2017, since (7+1)/2=4 is not prime, although 7 is prime.

Thus, the response to the first query should be 2.

Sample Input 2

4
13 13
7 11
7 11
2017 2017

Sample Output 2

1
0
0
1

Note that 2017 is also similar to 2017.

Sample Input 3

6
1 53
13 91
37 55
19 51
73 91
13 49

Sample Output 3

4
4
1
1
1
2

Solution in C (GCC 5.4.1) (judge verdict: Time Limit Exceeded)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int isPrime_( int num )
{
    int tmp =num- 1;
    if(num==1)
        return 0;
    if(num==0)
        return 0;
    for(int i= 2;i <=tmp; i++)
    {
        if(num %i== 0)
            return 0 ;
    }
    return 1 ;
    }
int main()
{
    int n;
    int a,b;
    scanf("%d",&n);
    while(n--)
    {
        scanf("%d%d",&a,&b);
        int cnt=0;
        for(int i=a;i<=b;i++)
        {
            if(i%2!=0)
            {
                int m=(i+1)/2;
                if((isPrime_(i)==1)&&(isPrime_(m)==1))
                   {
                       cnt++;
                   }
            }
        }
        printf("%d\n",cnt);
        cnt=0;
    }
    return 0;
}