4. A rival campaign manager believes that finding the best donors is the way to go.

They use the same dataset from the previous question to instead find all user

pairs (U,V) such that: (i) both U and V have at least 100 million followers each,

and (ii) U and V follow at least 100 accounts in common (excluding each other).

Note that U and V may or may not follow each other (either way)! Write a

Mapreduce program for this. Same instructions as the first Mapreduce question

in this series apply.