#include <bits/stdc++.h>
#include <boost/multiprecision/cpp_int.hpp>
using namespace std;

//#define int long long
//using ll = boost::multiprecision::cpp_int;
using ll = long long;
//const int INF = 1e9;//INT_MAX=1<<31-1=2147483647
const ll INF = (ll)1e18;//1<<63-1=9223372036854775807
const int MOD = (int)1e9 + 7;
const double EPS = 1e-9;
const int dx[4]={1,0,-1,0};
const int dy[4]={0,1,0,-1};
#ifdef LOCAL_ENV
	#define debug(var) std::cout<<#var" = "<<var<<std::endl
#else
	#define debug(var)
#endif
#define p(var) std::cout<<var<<std::endl
#define PI (acos(-1))
#define rep(i, n)   for(ll i=0, i##_length=(n); i< i##_length; ++i)
#define repeq(i, n) for(ll i=1, i##_length=(n); i<=i##_length; ++i)
#define all(a) (a).begin(), (a).end()
#define pb push_back
inline bool isnatural(double a) { return a>=0 && ceil(a)==floor(a); }
template<typename T> inline T gcd(T a, T b) { return b ? gcd(b,a%b) : a; }
template<typename T> inline T lcm(T a, T b) { return a / gcd(a,  b) * b; }
template<typename T1, typename T2>inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }
template<typename T1, typename T2>inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }
template<typename T1, typename T2> ostream& operator<<(ostream& s, const pair<T1, T2>& p) {return s << "(" << p.first << ", " << p.second << ")";}
template<typename T> ostream& operator<<(ostream& s, const vector<T>& v) {
	for (int i = 0, len = v.size(); i < len; ++i){
		s << v[i]; if (i < len - 1) s << "\t";
	}
	return s;
}
template<typename T> ostream& operator<<(ostream& s, const vector< vector<T> >& vv) {
	for (int i = 0, len = vv.size(); i < len; ++i){
		s << vv[i] << endl;
	}
	return s;
}
template<typename T1, typename T2> ostream& operator<<(ostream& s, const map<T1, T2>& m) {
	s << "{" << endl;
	for (typeof(m.begin()) itr = m.begin(); itr != m.end(); ++itr){
		s << "\t" << (*itr).first << " : " << (*itr).second << endl;
	}
	s << "}" << endl;
	return s;
}

/*-----8<-----8<-----*/


inline static void upflag(int *flags,int BITS,int i) {
	flags[i / BITS] |= 1 << (i % BITS);
}

inline static int getflag(int *flags,int BITS,int i) {
	return (flags[i / BITS] >> (i % BITS)) & 1;
}

//iが素数の時v[i]=true, 合成数の時v[i]=false なMAXVAL以下のvectorを返す
vector<bool> eratosthenes(int MAXVAL){
	int BITS = (sizeof(int) * 8);
	int FLAGS_NUM = (MAXVAL / BITS + 1);
	int flags[FLAGS_NUM] = {};
	int i, j, f, s, count = 2;
	int max = (int)sqrt(MAXVAL) + 1;
	vector<bool> primelist(MAXVAL+1,false);
	primelist[2] = true;
	primelist[3] = true;
	for (i = 5, f = 4; i <= max; i += (f = 6 - f)) {
		if (!getflag(flags,BITS,i)) {
			primelist[i] = true;
			s = MAXVAL / i;
			for (j = s - !(s & 1); j >= i; j -= 2) {
				if (!getflag(flags,BITS,i))
					upflag(flags,BITS,i*j);
			}
		}
	}
	for (; i <= MAXVAL; i += (f = 6 - f)){
		if (!getflag(flags,BITS,i)){
			primelist[i] = true;
		}
	}
	return primelist;
}


signed main() {
	int q;
	cin >> q;

	//素数上限
	int N=1e5;
	vector<bool> primelist;
	primelist=eratosthenes(N);

	vector<bool> primeppoilist(N+1,false);
	for(int i=3;i<N;i+=2){
		if(primelist[i] && primelist[(i+1)/2]){
			primeppoilist[i]=true;
		}
	}


	//平方分割してみる
	//1バケットに入っている要素数
	int bucket_size=floor(sqrt(N));
	//バケットの個数
	int bucket_num = (N + bucket_size - 1) / bucket_size;
	//バケット　バケット内に入っている2017っぽい数の個数
	vector<int> bucket(bucket_num,0);

	//バケットを作る
	int count=0;
	for(int i=3;i<N;i+=2){
		if(primeppoilist[i]){
			bucket[i/bucket_size]++;
		}
	}

	debug(" ");
	debug(bucket_size);
	debug(bucket_num);
	debug(bucket);
	
	vector<int> answerlist(q,0);
	rep(i,q){
		int x,y;
		cin >> x >> y;
		int answer=0;
		//バケットを走査
		// [x, y]の値を取得します　[x, y)がほしい場合はy-=1にしておいてね
		for (int i = 0; i < bucket_num; i++) {
			//bucket[i]の始点と終点
			int l = i * bucket_size;
			int r = (i + 1) * bucket_size - 1;
			//バケットの範囲外の場合はcontinue
			if (r < x || y < l){
				continue;
			}
			if (x <= l && r <= y) {
				//バケットが全て収まっている場合→バケットの値をそのまま使う
				answer += bucket[i];
			} else {
				//バケットの途中の場合→対象範囲を地道に調べる
				for (int j = max(x, l); j <= min(y, r); j++) {
					if(primeppoilist[j]){
						answer++;
					}
				}
			}
		}
		answerlist[i]=answer;
	}

	rep(i,q)p(answerlist[i]);
	return 0;
}



Measured memory_bytes: 1024