题解 | #合并表记录#

# 构建动态字典
n = int(input())
dic = {}

for i in range(n):
    line = input().split()
    key = int(line[0])
    value = int(line[1])
    if key in dic: dic[key] = dic[key] + value 
    else: dic[key] = value

for each in sorted(dic):
    print(each, dic[each])