description: Monocarp is playing a computer game. Now he wants to complete the first level of this game.
  
  A level is a rectangular grid of 2 rows and n columns. Monocarp controls a character, which starts in cell (1, 1) — at the intersection of the 1-st row and the 1-st column.
  
  Monocarp's character can move from one cell to another in one step if the cells are adjacent by side and/or corner. Formally, it is possible to move from cell (x_1, y_1) to cell (x_2, y_2) in one step if |x_1 - x_2| ≤ 1 and |y_1 - y_2| ≤ 1. Obviously, it is prohibited to go outside the grid.
  
  There are traps in some cells. If Monocarp's character finds himself in such a cell, he dies, and the game ends.
  
  To complete a level, Monocarp's character should reach cell (2, n) — at the intersection of row 2 and column n.
  
  Help Monocarp determine if it is possible to complete the level.
  
  Input
  
  The first line contains a single integer t (1 ≤ t ≤ 100) — the number of test cases. Then the test cases follow. Each test case consists of three lines.
  
  The first line contains a single integer n (3 ≤ n ≤ 100) — the number of columns.
  
  The next two lines describe the level. The i-th of these lines describes the i-th line of the level — the line consists of the characters '0' and '1'. The character '0' corresponds to a safe cell, the character '1' corresponds to a trap cell.
  
  Additional constraint on the input: cells (1, 1) and (2, n) are safe.
  
  Output
  
  For each test case, output YES if it is possible to complete the level, and NO otherwise.
  
  Example
  
  Input
  
  
  4
  3
  000
  000
  4
  0011
  1100
  4
  0111
  1110
  6
  010101
  101010
  
  
  Output
  
  
  YES
  YES
  NO
  YES
  
  Note
  
  Consider the example from the statement.
  
  In the first test case, one of the possible paths is (1, 1) → (2, 2) → (2, 3).
  
  In the second test case, one of the possible paths is (1, 1) → (1, 2) → (2, 3) → (2, 4).
  
  In the fourth test case, one of the possible paths is (1, 1) → (2, 2) → (1, 3) → (2, 4) → (1, 5) → (2, 6).
solution: import java.util.*;
  import java.io.*;
  
  @SuppressWarnings("unchecked")
  public class  Main implements Runnable {
      static InputReader in;
      static OutputWriter out;
  
      public static void main(String[] args) {
          new Thread(null, new Main(), "whatever", 1<<26).start();
      }
  
      public void run() {
          try {
              in = new InputReader();
              out = new OutputWriter();
  
              in.getTokens();
              int totalTestCases = in.nextInt();
  
              for(int testCase=0; testCase<totalTestCases; testCase++) {
                  in.getTokens();
                  int n = in.nextInt();
  
                  boolean[][] hasTrap = new boolean[2][n];
  
                  in.getTokens();
                  String str = in.nextStr();
                  for(int i=0; i<n; i++) {
                      hasTrap[0][i] = str.charAt(i) == '1';
                  }
  
                  in.getTokens();
                  str = in.nextStr();
                  for(int i=0; i<n; i++) {
                      hasTrap[1][i] = str.charAt(i) == '1';
                  }
  
                  boolean possible = true;
                  for(int i=1; i<n; i++) {
                      if(hasTrap[0][i] && hasTrap[1][i]) {
                          possible = false;
                          break;
                      }
                  }
  
                  out.println(String.format("%s", possible ? "YES" : "NO"));
              }
  
              out.close();
          } catch (Exception e) {
              e.printStackTrace();
          }
      }
  }
  
  class InputReader {
      private BufferedReader in;
      private String[] tokens;
      private int positionOfNextTokenToRead;
  
  
      public InputReader() throws IOException {
          in = new BufferedReader(new InputStreamReader(System.in));
  //        in = new BufferedReader(new FileReader("./resources/traffic_control_input.txt"));
      }
  
      public void getTokens() throws IOException {
          String nextLine = in.readLine().trim();
          tokens = nextLine.split(" ");
          positionOfNextTokenToRead = 0;
      }
  
      public String nextStr() {
          return tokens[positionOfNextTokenToRead++];
      }
  
      public Integer nextInt() {
          return Integer.parseInt(tokens[positionOfNextTokenToRead++]);
      }
  
      public Long nextLong() {
          return Long.parseLong(tokens[positionOfNextTokenToRead++]);
      }
  
      public Double nextDouble() {
          return Double.parseDouble(tokens[positionOfNextTokenToRead++]);
      }
  
      public String nextLine() throws IOException {
          return in.readLine().trim();
      }
  }
  
  class OutputWriter {
      private PrintWriter out;
  
  
      public OutputWriter() throws IOException {
          out = new PrintWriter(System.out, false);
  //        out = new PrintWriter("./resources/output.txt");
      }
  
      public void print(Object line) {
          out.print(line);
      }
  
      public void println(Object line) {
          out.println(line);
      }
  
      public void flush() {
          out.flush();
      }
  
      public void close() {
          out.close();
      }
  }
  