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
 i,n,l,r:longint;
 a,s:array[0..100001] of longint;
function sushu(x:longint):boolean;
var
 i:longint;
begin
 for i:=2 to trunc(sqrt(x)) do
  if x mod i=0 then exit(false);
 exit(true);
end; 
begin
 for i:=3 to 100000 do
  begin
   if sushu(i) and sushu((i+1) div 2) then
    inc(s[i]);
   s[i]:=s[i]+s[i-1];
  end;
 readln(n);
 for i:=1 to n do
  begin
   readln(l,r);
   a[i]:=s[r]-s[l-1];
  end;
 for i:=1 to n do writeln(a[i]);
end.