题解 | #合并表记录#

length = int(input())
numList = []
numDict = {}
for i in range(length):
    num = input().split()
    numList.append(num)

for n in numList:
    n1 = int(n[0])
    n2 = int(n[1])
    if n1 not in numDict.keys():
        numDict[n1] = n2
    else:
        numDict[n1] = numDict[n1] + n2

for k in sorted(numDict):
    print(k, numDict[k])