#include <atomic>
#include <iostream>
#include <mutex>
#include <unordered_map>
#include <vector>

using std::cin;
using std::cout;
using std::endl;

class ShoppingCart {
private:
	ShoppingCart() = default;

public:
	~ShoppingCart() = default;

	ShoppingCart(ShoppingCart const &other) = delete;
	ShoppingCart(ShoppingCart const &&other) = delete;
	ShoppingCart &operator=(ShoppingCart const &other) = delete;
	ShoppingCart &operator=(ShoppingCart const &&other) = delete;

	static ShoppingCart *GetInstance() {
		ShoppingCart *cart = mAtomic.load();
		if (cart == nullptr) {
			std::unique_lock<std::mutex> lock(mMutex);
			cart = mAtomic.load();
			if (cart == nullptr) {
				cart = new ShoppingCart;
				mAtomic.store(cart);
			}
		}
		return cart;
	}

	void addItem(std::string item, int cnt) {
		if (item.empty() or cnt <= 0)
			return;
		order.push_back(item);
		items[item] += cnt;
	}

	void showItem() {
		for (std::string const &item : order) {
			cout << item << " " << items[item] << endl;
		}
	}

private:
	std::unordered_map<std::string, int> items; // 保存购物车物品和数量
	std::vector<std::string> order;             // 保证购物车物品顺序

	static std::mutex mMutex;                   // 保证线程安全
	static std::atomic<ShoppingCart *> mAtomic; // 保证线程安全
};

std::atomic<ShoppingCart *> ShoppingCart::mAtomic;
std::mutex ShoppingCart::mMutex;

int main() {
	int cnt;
	std::string name;
	while (cin >> name >> cnt) {
		ShoppingCart::GetInstance()->addItem(name, cnt);
	}

	ShoppingCart::GetInstance()->showItem();

	return 0;
}