https://www.acmicpc.net/problem/20920 풀이 1import java.io.IOException;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.io.BufferedReader;import java.io.BufferedWriter;import java.util.StringTokenizer;import java.util.Map;import java.util.HashMap;import java.util.List;import java.util.ArrayList;public class Practice { public static void main(String[] args) throws I..