题意一定要看清楚 是 i I O 跟0 (不要看成 1 跟 I)
题意一定要看清楚 是 i I O 跟0 (不要看成 1 跟 I)
题意一定要看清楚 是 i I O 跟0 (不要看成 1 跟 I)

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()) {
            int T = sc.nextInt();
            while (T-- > 0) {
                int length = sc.nextInt();
                String str1 = sc.next();
                String str2 = sc.next();
                boolean flag = true;
                for (int i = 0; i < length; i++) {
                    if (str1.charAt(i) == str2.charAt(i)) {
                    } else {
                        if (str1.charAt(i) == 'O' && str2.charAt(i) == '0') {
                        } else if (str1.charAt(i) == '0' && str2.charAt(i) == 'O') {
                        } else if (str1.charAt(i) == 'I' && str2.charAt(i) == 'l') {
                        } else if (str1.charAt(i) == 'l' && str2.charAt(i) == 'I') {
                        } else {
                            flag = false;
                            System.out.println("NO");
                            break;
                        }
                    }
                }
                if (flag)
                    System.out.println("OK");
            }
        }
    }
}