Space Formula

Description:

Input:

The first line contains two integer numbers $$$N$$$ ($$$1 \leq N \leq 200000$$$) representing number of F1 astronauts, and current position of astronaut $$$D$$$ ($$$1 \leq D \leq N$$$) you want to calculate best ranking for (no other competitor will have the same number of points before the race).

The second line contains $$$N$$$ integer numbers $$$S_k$$$ ($$$0 \leq S_k \leq 10^8$$$, $$$k=1...N$$$), separated by a single space, representing current ranking of astronauts. Points are sorted in non-increasing order.

The third line contains $$$N$$$ integer numbers $$$P_k$$$ ($$$0 \leq P_k \leq 10^8$$$, $$$k=1...N$$$), separated by a single space, representing point awards for the next race. Points are sorted in non-increasing order, so winner of the race gets the maximum number of points.

Output:

Output contains one integer number — the best possible ranking for astronaut after the race. If multiple astronauts have the same score after the race, they all share the best ranking.

Sample Input:

4 3
50 30 20 10
15 10 7 3

Sample Output:

2

Note:

If the third ranked astronaut wins the race, he will have 35 points. He cannot take the leading position, but he can overtake the second position if the second ranked astronaut finishes the race at the last position.