import java.util.*;
import java.io.*;

public class Main{
    public static void main(String[] args){
        ArrayList<Integer> primes=eratosthenes(100000);
        int accum=0;
        int[] zeroToX=new int[100000];
        for(int x=0;x<100000;x++){
            if(primes.contains(x)&&primes.contains((x+1)/2)) accum++;
            zeroToX[x]=accum;
        }
        FastScanner fsc=new FastScanner();
        int q=fsc.nextInt();
        int l,r;
        StringBuilder sb=new StringBuilder("");
        for(int i=0;i<q;i++){
            l=fsc.nextInt();
            r=fsc.nextInt();
            sb.append((zeroToX[r]-zeroToX[l-1])+"\n");
        }
        fsc.close();
        System.out.print(sb);

    }

    public static ArrayList<Integer> eratosthenes(int n){
        boolean primes[]=new boolean[n];
        ArrayList<Integer> result =new ArrayList<Integer>();
        if(n>=2) result.add(Integer.valueOf(2));
        for(int i=3;i<n;i+=2){
            if(!primes[i]){
                result.add(Integer.valueOf(i));
                for(int j=i*i;j<n;j+=2*i){
                    if(j<0) break;
                    primes[j]=true;
                }
            }
        }
        return result;
    }

    static class FastScanner {
        private final InputStream in = System.in;
        private final byte[] buffer = new byte[1024];
        private int ptr = 0;
        private int buflen = 0;
        private boolean hasNextByte() {
            if (ptr < buflen) {
                return true;
            }else{
                ptr = 0;
                try {
                    buflen = in.read(buffer);
                } catch (IOException e) {
                    e.printStackTrace();
                }
                if (buflen <= 0) {
                    return false;
                }
            }
            return true;
        }
        private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
        private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
        public boolean hasNext() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; return hasNextByte();}
        public String next() {
            if (!hasNext()) throw new NoSuchElementException();
            StringBuilder sb = new StringBuilder();
            int b = readByte();
            while(isPrintableChar(b)) {
                sb.appendCodePoint(b);
                b = readByte();
            }
            return sb.toString();
        }
        public long nextLong() {
            if (!hasNext()) throw new NoSuchElementException();
            long n = 0;
            boolean minus = false;
            int b = readByte();
            if (b == '-') {
                minus = true;
                b = readByte();
            }
            if (b < '0' || '9' < b) {
                throw new NumberFormatException();
            }
            while(true){
                if ('0' <= b && b <= '9') {
                    n *= 10;
                    n += b - '0';
                }else if(b == -1 || !isPrintableChar(b)){
                    return minus ? -n : n;
                }else{
                    throw new NumberFormatException();
                }
                b = readByte();
            }
        }
        public int nextInt() {
            long nl = nextLong();
            if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException();
            return (int) nl;
        }
        public double nextDouble() { return Double.parseDouble(next());}
        public void close(){
            try{in.close();}
            catch(IOException e){e.printStackTrace();}
        }
    }
}

Measured memory_bytes: 45536