题解 | #合并表记录#

num = int(input())
dic1 = {}
for i in range(num):
    i_and_v = input()
    list1 = i_and_v.split(' ')
    if int(list1[0]) in dic1.keys():# 如果新的索引与原来索引有相同的，加入此指令实现对应值相加，而非覆盖
        dic1[int(list1[0])] += int(list1[1])
    else:
        dic1[int(list1[0])] = int(list1[1])
index_list = sorted(dic1)
for m in index_list:       #根据索引得到并输出值
    print(m,dic1[m],sep=' ')