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 Pascal (FPC 2.6.2) (judge verdict: Accepted)

var
 n,i,j,l,r,ans:longint;
 a:array[0..100005] of boolean;
 b:array[0..100005] of longint;
begin
 readln(n);
 a[1]:=true;
 for i:=2 to trunc(sqrt(100000)) do
  if not a[i] then
   for j:=2 to 100000 div i do
    a[i*j]:=true;
 b[1]:=0;
 b[2]:=0;
 for i:=1 to 100000 do
  if odd(i) and not a[i] and not a[(i+1) div 2] then b[i]:=b[i-1]+1 else b[i]:=b[i-1];
 for i:=1 to n do
  begin
   readln(l,r);
   writeln(b[r]-b[l-1]);
  end;
end.