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.Scanner;
  
  public class ComputerGame {
      public static void main(String[] args){
      
          // Problem statement link: https://codeforces.com/problemset/problem/1598/A
  
          Scanner scan = new Scanner(System.in);
          int testCase = scan.nextInt();
  
          while(testCase>0){
              int n = scan.nextInt();                         // n = Columns
              int[][] game = new int[2][n];                   // game grid [2 x n]
              scan.nextLine();
  
              String input1 = scan.nextLine();                // taking input for L1
              String[] line1 = input1.split("");
              String input2 = scan.nextLine();                // taking input for L2
              String[] line2 = input2.split("");
  
              for(int i=0; i<n; i++){
                  game[0][i] = Integer.parseInt(line1[i]);    // filling L1
              }
              for(int i=0; i<n; i++){
                  game[1][i] = Integer.parseInt(line2[i]);    // filling L2
              }
  
              boolean flag = false;
              for(int i=0; i<n; i++){
                  if(game[0][i] == 1 && game[1][i] == 1){
                      flag = true;
                      break;
                  }
              }
  
              System.out.println((flag == true) ? "NO" : "YES");
              testCase--;
          }
  
          scan.close();
      }
  }
  
  // sample test cases
  
  // input
  // 4
  // 3
  // 000
  // 000
  // 4
  // 0011
  // 1100
  // 4
  // 0111
  // 1110
  // 6
  // 010101
  // 101010
  
  // output
  // YES
  // YES
  // NO
  // YES
  