- Time limit: 1.00 s
- Memory limit: 512 MB
Killing a monster takes $sf$ time where $s$ is the monster's strength and $f$ is your skill factor (lower skill factor is better). After killing a monster, you get a new skill factor. What is the minimum total time in which you can win the game?
The first input line has two integers $n$ and $x$: the number of levels and your initial skill factor.
The second line has $n$ integers $s_1,s_2,\dots,s_n$: each monster's strength.
The third line has $n$ integers $f_1,f_2,\dots,f_n$: your new skill factor after killing a monster.
Print one integer: the minimum total time to win the game.
- $1 \le n \le 2 \cdot 10^5$
- $1 \le x \le 10^6$
- $1 \le s_1 \le s_2 \le \dots \le s_n \le 10^6$
- $x \ge f_1 \ge f_2 \ge \dots \ge f_n \ge 1$
20 30 30 50 90
90 60 20 20 10
Explanation: The best way to play is to kill the second and fifth monster.