content: import java.io.*;
  import java.math.*;
  import java.security.*;
  import java.text.*;
  import java.util.*;
  import java.util.concurrent.*;
  import java.util.regex.*;
  
  public class Solution {
  
      // Method to compute the value of XOR sequence
      static long xorSequence(long l, long r) {
          //The answer is the xor of value obtained by calc function of left and right range
          long answer = calc(r) ^ calc(l - 1);
          return answer;
      }
      //Perform xor of 7 with the limit passed and return on the basis of the conditions
      private static long calc(long limit) {
          switch ((int) (limit & 7)) {
              case 0:
                  return limit;
              case 1:
                  return limit;
              case 2:
                  return 2;
              case 3:
                  return 2;
              case 4:
                  return limit + 2;
              case 5:
                  return limit + 2;
              case 6:
                  return 0;
              case 7:
                  return 0;
              default:
                  throw new RuntimeException();
          }
      }
      /* Driver Code */
      private static final Scanner scanner = new Scanner(System.in);
      public static void main(String[] args) throws IOException {
          BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));
          int q = scanner.nextInt();
          scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
          for (int qItr = 0; qItr < q; qItr++) {
              String[] lr = scanner.nextLine().split(" ");
              long l = Long.parseLong(lr[0]);
              long r = Long.parseLong(lr[1]);
              long result = xorSequence(l, r);
              bufferedWriter.write(String.valueOf(result));
              bufferedWriter.newLine();
          }
          bufferedWriter.close();
          scanner.close();
      }
  }
  