6205：card card card

As a fan of Doudizhu, WYJ likes collecting playing cards very much.
One day, MJF takes a stack of cards and talks to him: let's play a game and if you win, you can get all these cards. MJF randomly assigns these cards into $n$ heaps, arranges in a row, and sets a value on each heap, which is called "penalty value".
Before the game starts, WYJ can move the foremost heap to the end any times.
After that, WYJ takes the heap of cards one by one, each time he needs to move all cards of the current heap to his hands and face them up, then he turns over some cards and the number of cards he turned is equal to the $penalty value$.
If at one moment, the number of cards he holds which are face-up is less than the $penalty value$, then the game ends. And WYJ can get all the cards in his hands (both face-up and face-down).
Your task is to help WYJ maximize the number of cards he can get in the end.So he needs to decide how many heaps that he should move to the end before the game starts. Can you help him find the answer?
MJF also guarantees that the sum of all "penalty value" is exactly equal to the number of all cards.

There are about $10$ test cases ending up with EOF.
For each test case:
the first line is an integer $n$ ($1\leq n\leq 10^6$), denoting $n$ heaps of cards;
next line contains $n$ integers, the $i$$th$ integer $a_i$ ($0\leq ai\leq 1000$) denoting there are $a_i$ cards in $i$$th$ heap;
then the third line also contains $n$ integers, the $i$$th$ integer $b_i$ ($1\leq bi\leq 1000$) denoting the "penalty value" of $i$$th$ heap is $b_i$.

For each test case, print only an integer, denoting the number of piles WYJ needs to move before the game starts. If there are multiple solutions, print the smallest one.