and are under suspicion of plagiarism, a serious crime at William Lyon Mackenzie CI. They were supposed to complete a project involving writing French words on a piece of paper in alphabetical order and presenting their definitions to the class. To see if they truly plagiarized, you are to write a program to determine how many unique words they share in common.
First line consists of ~N~ and ~M~ separated by a space (~0 \le N, M \le 10^6~, number of words on 's and 's respective projects), followed by ~N~ spaced strings on the second line, followed by ~M~ spaced strings on the third line.
Output the number of unique words they share in common.
4 4 a b c d b c z zz