That's how you start out.

Solution.java

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

public class Solution {
	
	public static void main(String args[]) throws NumberFormatException, IOException {
		final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		final int nTestcases = Integer.parseInt(br.readLine());
		final StringBuilder ret = new StringBuilder();
		
		for (int testcase = 1; testcase <= nTestcases; ++testcase) {
			int answer = 0;
			
			// solve
			
			ret.append('#');
			ret.append(testcase);
			ret.append(' ');
			ret.append(answer);
			ret.append('\n');
		} // for testcase
		
		System.out.println(ret);
	} // main()
	
} // public class