Q = int(input())
judge_arr = []
data = []
max_number = 0
for i in range(Q):
	x = input().split()
	data.append([int(x[0]),int(x[1])])
	if max_number<data[i][1]:
		max_number = data[i][1]


prime_arr = [2]

for i in range(3,max_number,2):
	c = 0
	for j in prime_arr:
		if j>i**0.5 or i%j!=0:
			break
		elif i%j==0:
			c = 1
	if c==0:
		if (i+1)/2 in prime_arr
			prime_arr.append(i)
			judge_arr.append(1)
		else:
			prime_arr.append(i)
			judge_arr.append(0)

#for n in range(len(prime_arr)):
	#if (prime_arr[n]+1)/2 in prime_arr:
		#judge_arr[n] = 1

def sumz(a,b):
	x = 0
	y = 0
	for n in range(len(prime_arr)):
		if prime_arr[n]<a:
			x = n
		if prime_arr[n]>b:
			y = n
			break
	return sum(judge_arr[x+1:y])



### FIXED CODE ###

import math
from collections import deque
from collections import defaultdict

import bisect

#自作関数群
def readInt():
	return int(input())
def readInts():
	return list(map(int, input().split()))
def readChar():
	return input()
def readChars():
	return input().split()
def factorization(n):
	res = []
	if n%2==0:
		res.append(2)
	for i in range(3,math.floor(n//2)+1,2):
		if n%i==0:
			c = 0
			for j in res:
				if i%j==0:
					c=1
			if c==0:
				res.append(i)
	return res
def fact2(n):
	p = factorization(n)
	res = []
	for i in p:
		c=0
		z=n
		while 1:
			if z%i==0:
				c+=1
				z/=i
			else:
				break
		res.append([i,c])
	return res
def fact(n):#階乗
	ans = 1
	m=n
	for _i in range(n-1):
		ans*=m
		m-=1
	return ans
def comb(n,r):#コンビネーション
	if n<r:
		return 0
	l = min(r,n-r)
	m=n
	u=1
	for _i in range(l):
		u*=m
		m-=1
	return u//fact(l)
def combmod(n,r,mod):
	return (fact(n)/fact(n-r)*pow(fact(r),mod-2,mod))%mod
def printQueue(q):
	r=copyQueue(q)
	ans=[0]*r.qsize()
	for i in range(r.qsize()-1,-1,-1):
		ans[i] = r.get()
	print(ans)
class UnionFind():
	def __init__(self, n):
		self.n = n
		self.parents = [-1]*n

	def find(self, x): # root
		if self.parents[x]<0:
			return x
		else:
			self.parents[x] = self.find(self.parents[x])
			return self.parents[x]

	def union(self,x,y):
		x = self.find(x)
		y = self.find(y)

		if x==y:
			return

		if self.parents[x]>self.parents[y]:
			x,y = y,x

		self.parents[x]+=self.parents[y]
		self.parents[y]=x

	def size(self,x):
		return -1*self.parents[self.find(x)]

	def same(self,x,y):
		return self.find(x)==self.find(y)

	def members(self,x): # much time
		root = self.find(x)
		return [i for i in range(self.n) if self.find(i)==root]

	def roots(self):
		return [i for i,x in enumerate(self.parents) if x<0]

	def group_count(self):
		return len(self.roots())

	def all_group_members(self):
		return {r: self.members(r) for r in self.roots()} # 1~n
def bitArr(n):#ビット全探索
	x = 1
	zero = "0"*n
	ans = []
	ans.append([0]*n)
	for i in range(2**n-1):
		ans.append(list(map(lambda x:int(x),list((zero+bin(x)[2:])[-1*n:]))))
		x+=1
	return ans;
def arrsSum(a1,a2):
	for i in range(len(a1)):
		a1[i]+=a2[i]
	return a1
def maxValue(a,b,v):
	v2 = v
	for i in range(v2,-1,-1):
		for j in range(v2//a+1): #j:aの個数
			k = i-a*j
			if k%b==0:
				return i
	return -1
def copyQueue(q):
	nq = queue.Queue()
	n = q.qsize()
	for i in range(n):
		x = q.get()
		q.put(x)
		nq.put(x)
	return nq
def get_sieve_of_eratosthenes(n):
	data = [2]
	for i in range(3,n+1,2):
		data.append(i)
		data.append(0)
	for i in range(len(data)):
		interval = data[i]
		if interval!=0:
			for j in range(i+interval,n-1,interval):
				data[j] = 0
	ans = [x for x in data if x!=0]
	return ans

q = readInt()
lr = []

maxNumber = 100000

for i in range(q):
	lr.append(readInts())


pri = get_sieve_of_eratosthenes(maxNumber)
simi = []

for i in range(1,len(pri)):
	if pri[bisect.bisect_left(pri,(pri[i]+1)//2)]==(pri[i]+1)//2:
		simi.append(pri[i])

for item in lr:
	print(len(simi[bisect.bisect_left(simi,item[0]):bisect.bisect_right(simi,item[1])]))