The first line of input contains N (1≤N≤100,000) and K (0≤K<N).
The next N lines describe the order, by breed ID, of fields on one side of the road;
each breed ID is an integer in the range 1…N. The last N lines describe the order, by breed ID,
of the fields on the other side of the road. Each breed ID appears exactly once in each ordering.