#include <bits/stdc++.h>
#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define FORR(i,a,b) for (int i=(a);i>=(b);i--)
#define pb push_back
#define pcnt __builtin_popcount
#define show(x) cout<<#x<<" = "<<x<<endl;
#define maxs(x,y) x = max(x,y)
#define mins(x,y) x = min(x,y)
#define fi first
#define se second
#define rng(a) (a.begin()),(a.end())
#define each(it,c) for(__typeof((c).begin()) it=(c).begin();it!=(c).end();it++)
#define sz(x) (int)(x).size()
#define mp make_pair

using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<pii> vpii;
typedef set<int> si;
typedef pair<ll,ll> pll;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<pll> vpll;
typedef set<ll> sl;
typedef __int128_t lll;
typedef pair<lll,lll> plll;
typedef vector<lll> vlll;
template<typename T>string join(vector<T>&v)
{stringstream s;FOR(i,0,sz(v))s<<' '<<v[i];return s.str().substr(1);}
template<typename A, size_t N, typename T>void Fill(A (&array)[N], const T&v)
{fill((T*)array,(T*)(array+N),v);}
ll gcd(ll a,ll b){if(a>b)swap(a,b);for(;a>0;b%=a,swap(a,b));return b;}
int modpow(ll a,ll n,int m){if(a==0)return a;ll p=1;for(;n>0;n/=2,a=a*a%m)if(n&1)p=p*a%m;return(int)p;}
void dout(double d){printf("%.12f\n",d);}

const int iinf = 1e9;
const ll linf = 1e18;
const int mod = 1e9+7;
const double pi = acos(-1);
const double eps = 1e-10;

struct SegTree{
  typedef int T;
  T e = 0;
  T m(const T&a, const T&b){return a + b;}
//###################################################
  typedef int i;i n;vector<T> d;
  void init(i m){n=1<<(32-__builtin_clz(m-1));d.resize(2*n-1);FOR(j,0,2*n-1)d[j]=e;}
  void init(vector<T>&v){n=1<<(32-__builtin_clz(sz(v)-1));d.resize(2*n-1);FOR(j,0,sz(v))d[j+n-1]=v[j];FORR(k, n-2, 0)d[k]=m(d[k*2+1],d[k*2+2]);}
  void update(i k,T a){k+=n-1;d[k]=a;while(k>0){k=(k-1)/2;d[k]=m(d[k*2+1],d[k*2+2]);}}
  T q(i a,i b,i k,i l,i r){return (r<=a||b<=l)?e:(a<=l&&r<=b)?d[k]:m(q(a,b,k*2+1,l,(l+r)/2),q(a,b,k*2+2,(l+r)/2,r));}
  T query(i a,i b){return q(a,b,0,0,n);}
};

struct Prime{
  vl pl;
  random_device rnd;
  mt19937_64 mt;
  Prime(){
    mt = mt19937_64(rnd());
  }
  __int128_t mp(ll _a,ll n,ll m){
    if(_a==0)return 0;
    __int128_t a=_a, p=1;
    for(;n>0;n/=2,a=a*a%m)if(n&1)p=p*a%m;
    return p;
  }
  bool miller_rabin(ll _n){
    __int128_t n, t, y;
    ll a, d;
    _n = abs(_n);
    if(_n==2) return true;
    if(_n==1||(_n&1)==0) return false;
//    cout << "miller::" << _n << endl;
    uniform_int_distribution<ll> dist(1, _n-1);
    n = __int128_t(_n);
    d = _n-1;
    while((d&1)==0) d>>=1;
//    cout << "d::" << d << endl;
    FOR(i, 0, 100){
      a = dist(mt);
      t = d;
      y = mp(a,t,_n);
      while(t != _n-1 && y != 1 &&y != n-1){
        y = (y*y)%_n;
        t <<= 1;
      }
      if(y != _n-1 && (t&1) == 0) return false;
    }
    return true;
  }
  bool is_prime(ll a){
    if(a < 2)return false;
    each(itr, pl){
      if(*itr * *itr > a)return true;
      if(a%*itr == 0)return false;
    }
    return true;
  }
  void init(int a){
    pl.resize(0);
    pl.pb(2);
    pl.pb(3);
    int i = 5;
    while(i <= a){
      if(is_prime(i)) pl.pb(i);
      i += 2;
      if(is_prime(i)) pl.pb(i);
      i += 4;
    }
  }
  void prime_division(ll a, vpii&v){ // vに素因数分解の結果が入る
    v.resize(0);
    for(vl::iterator itr = pl.begin(); *itr * *itr <= a; itr++){
      if(a%*itr == 0){
        ll c = 0;
        while((a%*itr) == 0){
          a /= *itr;
          c++;
        }
        v.pb(pii(*itr, c));
      }
    }
    if(a > 1)v.pb(pii(a, 1));
  }
  void divisor(ll a, vl&v){ // v に約数が入る
    v.pb(1);
    for(vl::iterator itr = pl.begin(); *itr * *itr <= a; itr++){
      if(a%*itr == 0){
        ll b = 1, vs = sz(v);
        while((a%*itr) == 0){
          a /= *itr;
          b *= *itr;
          FOR(j, 0, vs)v.pb(v[j] * b);
        }
      }
    }
    if(a>1){
      int vs = sz(v);
      FOR(j, 0, vs)v.pb(v[j] * a);
    }
  }
};
SegTree seg;
Prime pr;
int q;
vi v(100005);

main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  pr.init(1000);
  FOR(i, 0, 100005) if(pr.is_prime(i) && pr.is_prime((i+1)/2)) v[i] = 1;
  seg.init(v);
  cin >> q;
  FOR(i, 0, q){
    int l, r;
    cin >> l >> r;
    cout << seg.query(l, r+1) << "\n";
  }
  return 0;
}

Measured memory_bytes: 2048