count = int(input()) ret = {} for _ in range(count): k, v = map(int, input().split()) if k in ret: ret[k] += v else: ret[k] = v keys = list(ret.keys()) keys.sort() for k in keys: print(k, ret[k])
count = int(input()) ret = {} for _ in range(count): k, v = map(int, input().split()) if k in ret: ret[k] += v else: ret[k] = v keys = list(ret.keys()) keys.sort() for k in keys: print(k, ret[k])