Need help with Python code with best performance T$2$

A group of friends is going on holiday together. They have come to a meeting point $($the start of the journey$)$ using $N$ cars. There are $P[K]$ people and $S[K]$ seats in the $K-$th car for $K$ in range $0..N-1.$ Some of the seats in the cars may be free, so it is possible for some of the friends to change the car they are in$.$ The friends have decided that, in order to be ecological, they will leave some cars parked at the meeting point and travel with as few cars as possible.

Write a function:

def solution$((P,S)$

that, given two arrays $P$ and $S,$ consisting of $N$ integers each, returns the minimum number of cars needed to take all of the friends on holiday.

Examples:

Given $P=[1,4,1]$ and $S=[1,5,1],$ the function should return $2.$ A person from car number $0$ can travel in car number $1$ instead. This way, car number $0$ can be left parked at the meeting point.

Given $P=[4,4,2,4]$ and $S=[5,5,2,5],$ the function should return $3.$ One person from car number $2$ can travel in car number $0$ and the other person from car number $2$ can travel in car number $3.$

Given $P=[2,3,4,2]$ and $S=[2,5,7,2],$ the function should return $2.$ Passengers from car number $0$ can travel in car number $1$ and passengers from car number $3$ can travel in car number $2.$

Write an efficient algorithm for the following assumptions:

$N$ is an integer within the range $[1.\mathrm{.}100,000]$;

each element of arrays $P$ and $S$ is an integer within the range $[1.\mathrm{.}9]$;