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: Runtime Error)

import math
def eratosthenes(n):
    prime_list = []
    num_list=[i for i in range(2, n+1)]
    limit = math.sqrt(n)
    while True:
        if limit <= num_list[0]:
            return prime_list + num_list
        prime_list.append(num_list[0])
        num_list = [e for e in num_list if e % num_list[0] != 0]

ls = eratosthenes(100000)
ls2 = []
count = 0
for i in ls:
    ls2.append(count)
    if (i+1)//2 in ls:
        count += 1
Q = int(input())
for i in range(Q):
    l, r = map(int, input().split())
    print(ls2[r-1]-ls2[l-1])