Build a dictionary, where the strings are the keys, and the values are the sum total of all of the values you've seen for that line. Once you hit the end of the input, print out the sum for each string, one per line. Sort your lines by the values, in reverse order. If there are two strings with the same value, then sort those strings by the string itself. So, if your input looks like this: 10 asdf jkl 3 asdf -1 17 foobar bbbb 17 then your output should be: bbbb 17 foobar 17 asdf 9 jkl 3