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<bits/stdc++.h>
using namespace std;
#define m 100005
int a[m],b[m],d[m];
int main()
  {
    int T,s,p=1;
    memset(a,1,sizeof(a));
    for(int i=2;i<m;i++)
      for(int j=2*i;j<=m;j+=i)
        a[j]=0;
    cin>>T;
    for(int i=1;i<=T;i++)
    cin>>b[i]>>d[i];
    while(T--){
    s=0;
    for(int i=b[p];i<=d[p];i++){
    if(a[i]&&a[(i+1)/2]&&(i+1)%2==0&&i!=1)
    s++;}
    p++;
    cout<<s<<endl;}
    return 0;
  }