题解 | #合并表记录#

row = int(input())  # 行数
hash_table = {}  # 创建空哈希表

for _ in range(row):
    items = input().split(" ")
    key = int(items[0])
    value = int(items[1])

    if not hash_table.get(key):
        hash_table.setdefault(key, value)
    else:
        hash_table[key] += value

sorted_keys = sorted(hash_table)
for key in sorted_keys:
    print(f"{key} {hash_table.get(key)}")