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 (3.4.3) (judge verdict: Wrong Answer)

import sys
import bisect
import math
input = sys.stdin.readline

n = int(input())
l = [list(map(int, input().split())) for _ in range(n)]

mc = max(l)[1]
mc_sqrt = math.sqrt(mc)

sys.exit()

prime = [i for i in range(2, mc + 1)]
c = 0
while True:
    if c >= len(prime):
        break
    t = prime[c]
    prime = [v for v in prime if v == t or v % t != 0]
    c = c + 1
    if c >= mc_sqrt:
        break
        
cum = [0 for i in range(mc + 1)]
for i in range(len(cum)):
    prime_index = bisect.bisect_left(prime, i)
    
    n2 = (i + 1) / 2
    prime_index2 = bisect.bisect_left(prime, n2)
    if len(prime) > prime_index and len(prime) > prime_index2 and prime[prime_index] == i and prime[prime_index2] == n2:
        cum[i] = cum[i - 1] + 1
    else:
        if i - 1 < 0:
            cum[i] = 0
        else:
            cum[i] = cum[i - 1]
        
for x, y in l:
    p = cum[x] - cum[x - 1]
    if x != y:
        p += cum[y] - cum[x]
    print(p)