题解 | #合并表记录#

n = int(input())
numbers = {}
groups = []
for _ in range(n):
    a, b = map(int, input().split())
    groups.append((a, b))
for g in groups:
    if g[0] in numbers:
        numbers[g[0]] += g[1]
    else:
        numbers[g[0]] = g[1]
numbers = dict(sorted(numbers.items()))
for k, v in numbers.items():
    print(f"{k} {v}")