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 Python (3.8.2) (judge verdict: Accepted)

#クエリにO(1)で返すためのテーブルを用意
import numpy as np
MAX = int(10e5+1)
List = list(range(2,MAX))
P = []
while len(List) > 0:
    p = List[0]
    if p >= np.sqrt(MAX): break
    P.append(p)
    List = [x for x in List if x % p != 0]
P = set(P+List)

Ans = [0] * MAX
cnt = 0
for i in range(1,MAX):
    if i in P and (i+1)//2 in P:
        cnt += 1
    Ans[i] = cnt

q = int(input())
for i in range(q):
    l, r = map(int, input().split())
    print(Ans[r]-Ans[l-1])