合并输入的一组数据

import java.io.*;

import java.util.*;

public class Main {

public static void main(String[] args) throws Exception {

Scanner scanner = new Scanner(System.in);

// 输出结果要求有序！

TreeMap<Integer, Integer> treeMap = new TreeMap<>();

while (scanner.hasNextInt()) {

int n = scanner.nextInt();

for (int i = 0; i < n; i++) {

int first = scanner.nextInt();

int second = scanner.nextInt();

treeMap.put(first, treeMap.getOrDefault(first, 0) + second);

}

}

for (Integer key : treeMap.keySet()) {

System.out.println(key + " " + treeMap.get(key));

}

}

}