https://www.acwing.com/problem/content/description/4592/

import java.io.*;
import java.util.*;

class Main {

    static int n;

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String[] s = br.readLine().split(" ");
        n = Integer.parseInt(s[0]);
        for (int i = 1; i <= n; i ++) {
            s = br.readLine().split(" ");
            String a = s[0];
            long b = Long.parseLong(s[1]);
            if (a.charAt(0) == '-') a = a.substring(1, a.length());
            if (check(a, b)) {
                System.out.println("Case " + i + ": divisible");
            }
            else System.out.println("Case " + i + ": not divisible");
        }
    }

    /**
     * ~~~不对
     * 取模运算的加法规则
     * (n + m) % p == (n % p + m % p) % p
     * 在这个例子中就是：n = 7678123668327637674887634, m = 101
     * 7678123668327637674887634 % 101 == (70000000... + 678123668327637674887634) % 101 == 
     * 依次类推，
     * ~~~
     * 
     * 这里是模拟手算的过程
     */
    private static boolean check(String a, long b) {
        // System.out.println("a[0] = " + a.charAt(0));
        long r = 0;  // 余数
        for (int i = 0; i < a.length(); i ++) {
            r = r * 10 + a.charAt(i) - '0';
            r %= b;
        }
        if (r == 0) return true;
        return false;
    }
}