The end of course is near! In a nursery, the educators have collected information about the toys that each girl and each boy like. To do it, the educators ask the children which is the toy they want to play with, and write down in a list the name of the boy/girl and the chosen toy.
The educators have asked you to write a program that counts the number of appearances of each pair child/toy.
Input
The input starts with a natural number n ≥ 1. Afterwards, there is a list with the n pairs of child’s name/toy. The names of the children are formed only by lowercase letters and digits.
Output
For each pair child/toy, print a line indicating how many times appears this pair. The list must be sorted by the name of the child, using the name of the toy as second criterion. Follow the format of the instances.
Observation
Some input lists can be very large. For this reason, your program must be efficient. We suggest you to use the function |sort()| to sort tuples (|struct|s).
Input
16 arnold train bill blocks albert doll1 ronnie ball martha blocks arnold doll2 arnold doll2 ronnie ball nancy doll1 albert doll1 martha doll1 arnold doll2 martha train arnold ball ronnie ball albert blocks
Output
albert blocks 1 albert doll1 2 arnold ball 1 arnold doll2 3 arnold train 1 bill blocks 1 martha blocks 1 martha doll1 1 martha train 1 nancy doll1 1 ronnie ball 3
Input
13 nancy book nancy train arnold book arnold ball arnold train arnold train arnold train bill book eythan tiger carla ball carla ball bob doll robert train
Output
arnold ball 1 arnold book 1 arnold train 3 bill book 1 bob doll 1 carla ball 2 eythan tiger 1 nancy book 1 nancy train 1 robert train 1
Input
3 biel train biel train biel train
Output
biel train 3