#!/usr/bin/env python3

import sys

def sum_file(inp, results):
    for line in inp:
        (key, number) = line.split(maxsplit=1)
        results[key] = results.get(key, 0) + int(number)

def main():
    sums = {}
    if len(sys.argv) == 1:
        sum_file(sys.stdin, sums)
    else:
        for filename in sys.argv[1:]:
            with open(filename, "r") as inp:
                sum_file(inp, sums)
    for key, sum in sums.items():
        print(f"{key} {sum}")

if __name__ == "__main__":
    main()