링크 : https://www.acmicpc.net/problem/2775
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
public class Main {
static int Recursion(int k, int n)
{
int answer=0;
if(k==0)
return n;
for(int i=1; i<=n;i++)
answer+=Recursion(k-1, i);
return answer;
}
public static void main(String[] args) throws NumberFormatException, IOException {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
int T = Integer.parseInt(reader.readLine());
int[] answer = new int[T];
for(int i=0; i<T;i++)
{
int k=Integer.parseInt(reader.readLine());
int n=Integer.parseInt(reader.readLine());
answer[i] = Recursion(k, n);
}
for(int num:answer)
System.out.println(num);
}
}