题解 | #合并表记录#

round = int(input()) #输入数据的次数
while True:
    try:
        dict={} #创建字典接收数据
        for i in range(round):
            data = input().split(' ')
            index = int(data[0]) #获取索引
            qty = int(data[1]) #获取值
            dict[index] = dict.get(index, 0)+qty #若索引不在字典内，直接添加; 若存在，累加
        for i in sorted(dict.keys()): #按顺序索引输出
            print('{0} {1}'.format(i, dict[i]))
    except:
        break