第二题AC代码（参考）：
import java.util.Scanner;

public class Main {

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int k = sc.nextInt();
    int m = sc.nextInt();
    sc.close();

    int minTime = 0;
    if(n >= m) {
        minTime = n * k / m;
        if((n * k) % m != 0) {
            minTime++;
        }
    } else {
        minTime = k;
    }
    System.out.println(minTime);
}

}