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.BufferedReader;
  import java.io.BufferedWriter;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.OutputStreamWriter;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  
  public class Main {
      public static void main(String[] args) throws IOException {
         
              BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
              BufferedWriter log = new BufferedWriter(new OutputStreamWriter(System.out));
  
           
           long t=Integer.parseInt(br.readLine().trim());
           while(t-->0){
               
             int n = Integer.parseInt(br.readLine().trim());
              int arr[][] = new int[2][n];
              String s1 = br.readLine();
              String s2 = br.readLine();
              boolean istrue = true;
              int p=1;
               for(int i=0; i<n; i++){
                   arr[0][i] = s1.charAt(i);
                   arr[1][i] = s2.charAt(i);
               }
               for(int i=0; i<n-1; i++){
                   
                   if(p==1){
                       if(s1.charAt(i)=='1'){
                           istrue = false;
                           break;
                       }
                       if(s2.charAt(i+1)=='0'){
                           p=2;
                           continue;
                       }
                      
                       else if(s1.charAt(i+1)=='0'){
                           p=1;
                           continue;
                       }
                       else if(s2.charAt(i)=='0'){
                          p=2;
                          continue;
                      }
                       else{
                           istrue = false;
                           break;
                       }
                   }
                   else if(p==2){
                       if(s2.charAt(i)=='1'){
                           istrue = false;
                           break;
                       }
                      if(s1.charAt(i+1)=='0'){
                          p=1;
                          continue;
                      }
                     
                      else if(s2.charAt(i+1)=='0'){
                          p=2;
                          continue;
                      }
                      else if(s1.charAt(i)=='0'){
                          p=1;
                          continue;
                      }
                      else{
                          istrue = false;
                          break;
                      }
                   }
              }
              if(istrue){
                  System.out.println("YES");
              }
              else
              System.out.println("NO");
          }
              br.close();
              log.flush();
          
      }   // end-main
  
      static void print(int arr[]) {
          System.out.print("Print :- ");
          for(int i=0 ; i<arr.length ; i++) {
              System.out.print(arr[i]+" ");
          }
          System.out.println();
      }   // end-print
      
  
  }
  