题解 | #合并表记录#

import sys

data_dict = {}
dict_size = int(input())
i = 0
while i < dict_size:
    k, v = input().split()
    # print(k+" "+v)
    if int(k) in data_dict.keys():
        data_dict[int(k)] += int(v)
    else:
        data_dict[int(k)] = int(v)
    i += 1
for k,v in sorted(data_dict.items()):
    print(str(k)+" "+ str(v))