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.IOException;
  import java.io.InputStream;
  import java.io.PrintWriter;
  import java.util.InputMismatchException;
  
  public class Main {
  
      public static void main(String[] args) {
          test();
      }
  
      private static void test() {
          InputReader sc = new InputReader(System.in);
          PrintWriter w = new PrintWriter(System.out);
  
          int t = sc.nextInt();
  
          for (int j = 0; j < t; j++) {
              int n = sc.nextInt();
  
              String str0 = sc.nextLine();
              String str1 = sc.nextLine();
  
              boolean ok = true;
              for (int i = 0; i < n; i++) {
                  if ((str0.charAt(i) == str1.charAt(i)) && str0.charAt(i) == '1') {
                      ok = false;
                      break;
                  }
              }
              w.println(ok ? "YES" : "NO");
          }
          w.close();
      }
  }
  
  class InputReader {
  
      private final InputStream stream;
      private final byte[] buf = new byte[8192];
      private int curChar, snumChars;
      private SpaceCharFilter filter;
  
      public InputReader(InputStream stream) {
          this.stream = stream;
      }
  
      public int snext() {
          if (snumChars == -1)
              throw new InputMismatchException();
          if (curChar >= snumChars) {
              curChar = 0;
              try {
                  snumChars = stream.read(buf);
              } catch (IOException e) {
                  throw new InputMismatchException();
              }
              if (snumChars <= 0)
                  return -1;
          }
          return buf[curChar++];
      }
  
      public int nextInt() {
          int c = snext();
          while (isSpaceChar(c)) {
              c = snext();
          }
          int sgn = 1;
          if (c == '-') {
              sgn = -1;
              c = snext();
          }
          int res = 0;
          do {
              if (c < '0' || c > '9')
                  throw new InputMismatchException();
              res *= 10;
              res += c - '0';
              c = snext();
          } while (!isSpaceChar(c));
          return res * sgn;
      }
  
      public long nextLong() {
          int c = snext();
          while (isSpaceChar(c)) {
              c = snext();
          }
          int sgn = 1;
          if (c == '-') {
              sgn = -1;
              c = snext();
          }
          long res = 0;
          do {
              if (c < '0' || c > '9')
                  throw new InputMismatchException();
              res *= 10;
              res += c - '0';
              c = snext();
          } while (!isSpaceChar(c));
          return res * sgn;
      }
  
      public int[] nextIntArray(int n) {
          int a[] = new int[n];
          for (int i = 0; i < n; i++) {
              a[i] = nextInt();
          }
          return a;
      }
  
      public String readString() {
          int c = snext();
          while (isSpaceChar(c)) {
              c = snext();
          }
          StringBuilder res = new StringBuilder();
          do {
              res.appendCodePoint(c);
              c = snext();
          } while (!isSpaceChar(c));
          return res.toString();
      }
  
      public String nextLine() {
          int c = snext();
          while (isSpaceChar(c))
              c = snext();
          StringBuilder res = new StringBuilder();
          do {
              res.appendCodePoint(c);
              c = snext();
          } while (!isEndOfLine(c));
          return res.toString();
      }
  
      public boolean isSpaceChar(int c) {
          if (filter != null)
              return filter.isSpaceChar(c);
          return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
      }
  
      private boolean isEndOfLine(int c) {
          return c == '\n' || c == '\r' || c == -1;
      }
  
      public interface SpaceCharFilter {
          public boolean isSpaceChar(int ch);
      }
  }
  
  