def func(): while True: try: num = int(input().strip()) md = {} for i in range(num): key, value = map(int, input().strip().split(" ")) md[key] = md.get(key, 0) + value for i in sorted(md): # 重点在sorted()方法对字典排序,否则会报错,我栽在这上面了-。- print(i, md[i]) except: break if __name__ == "__main__": func()