Small PhD Restaurant

"There is probably a place where all waiters have a PhD in, I don't know, some stuff." Dudu, 2014

Dudu is hungry, so he sat down in a Thai restaurant. Only after taking his seat did he realize where he was: the PhD restaurant, where every staff member holds a doctorate in some stuff.

Each staff member also prepared one challenge from his or her own field, and Dudu attempts those challenges while he waits for his food. Attempting the challenge of staff member $i$ costs $A_i$, and completing it pays $B_i$.

Each challenge can be completed at most once, and they can be attempted in any order. Dudu is smart enough to complete any challenge, but he must be able to pay $A_i$ before he attempts challenge $i$. Dudu starts with $M$ money. Find the largest amount he can end up with.

The first line contains two integers $N$ and $M$, the number of challenges and the money Dudu starts with.

The second line contains $N$ integers $A_1, A_2, \dots, A_N$, where $A_i$ is the cost of attempting challenge $i$.

The third line contains $N$ integers $B_1, B_2, \dots, B_N$, where $B_i$ is the payoff for completing challenge $i$.

• $1 \le N \le 1000$
• $0 \le M, A_i, B_i \le 10^6$

Print one integer, the maximum amount of money Dudu can obtain.

In the first example Dudu starts with 100 and can proceed in this order.

• Pay 80, get 90 back. Dudu now has 110.
• Pay 50, get 70 back. Dudu now has 130.
• Pay 110, get 150 back. Dudu now has 170.