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: Wrong Answer)

#include<iostream>
#include<math.h> 
using namespace std;



bool yy(long long a){
	
	int i,flag = true;
	int k = sqrt(a);
  	for (i = 2; i <= k; i++) 
	{
	    if (a % i == 0) 
		{
	      flag = false;
	      break;
	    }
  	}
  	return flag;
}

int main(){
	long long T;
	cin>>T;
	while(T)
	{
		
		long long j,k,sum=0;
		cin>>j>>k;
		for(long long i=j;i<=k;i++)
			if(yy(i)&&yy((i+1)/2))
				sum++;
		cout<<sum<<endl;
		
		
		
		T--;
	}	
}