题解 | #合并表记录#

n = input()
strList = []
strMap = {}
for i in range(int(n)):
    strList.append(input())

for str in strList:
    key, value = str.split(" ")[0], str.split(" ")[1]
    if int(key) not in strMap:
        strMap[int(key)] = int(value)
    else:
        strMap[int(key)] += int(value)


for kv in sorted(strMap):
    print(f"{kv} {strMap[kv]}")