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.io.*;
  import java.util.StringTokenizer;
  
  import static java.lang.Double.parseDouble;
  import static java.lang.Integer.parseInt;
  import static java.lang.Long.parseLong;
  import static java.lang.System.getProperty;
  import static java.lang.System.in;
  
  public class Main {
  
      public static void main(String[] args) {
          try (FastScanner scanner = getProperty("ONLINE_JUDGE", "").isEmpty() ? new FastScanner(new File("test.txt")) : new FastScanner(in)) {
              int T = scanner.nextInt();
              for (int t = 1; t <= T; ++t) {
                  int    N  = scanner.nextInt();
                  String L1 = scanner.nextString();
                  String L2 = scanner.nextString();
                  System.out.println(new Main(N, L1, L2).solve());
              }
          }
          catch (Exception e) {
              e.printStackTrace();
          }
      }
  
      private final int    N;
      private final String L1;
      private final String L2;
  
      public Main(int n, String l1, String l2) {
          N  = n;
          L1 = l1;
          L2 = l2;
      }
  
      private String solve() {
          for (int i = 0; i < N; i++) {
              if (L1.charAt(i) == '1' && L2.charAt(i) == '1') return "NO";
          }
          return "YES";
      }
  
      static class FastScanner implements AutoCloseable {
          final BufferedReader bufferedReader;
          StringTokenizer stringTokenizer;
  
          private FastScanner(File file) throws FileNotFoundException {
              bufferedReader = new BufferedReader(new FileReader(file));
          }
  
          private FastScanner(InputStream in) {
              bufferedReader = new BufferedReader(new InputStreamReader(in));
          }
  
          @Override
          public void close() throws Exception {
              bufferedReader.close();
          }
  
          public String nextString() throws IOException {
              return nextToken();
          }
  
          public int nextInt() throws IOException {
              return parseInt(nextToken(), 10);
          }
  
          public double nextDouble() throws IOException {
              return parseDouble(nextToken());
          }
  
          public long nextLong() throws IOException {
              return parseLong(nextToken(), 10);
          }
  
          public int[] nextIntArray(int n) throws IOException {
              int[] res = new int[n];
              for (int i = 0; i < n; ++i) {
                  res[i] = nextInt();
              }
              return res;
          }
  
          public long[] nextLongArray(int n) throws IOException {
              long[] res = new long[n];
              for (int i = 0; i < n; ++i) {
                  res[i] = nextLong();
              }
              return res;
          }
  
          public String[] nextStringArray(int n) throws IOException {
              String[] res = new String[n];
              for (int i = 0; i < n; ++i) {
                  res[i] = nextString();
              }
              return res;
          }
  
          private String nextToken() throws IOException {
              while (stringTokenizer == null || !stringTokenizer.hasMoreTokens()) {
                  stringTokenizer = new StringTokenizer(bufferedReader.readLine());
              }
              return stringTokenizer.nextToken();
          }
  
      }
  }
  