import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
            int n = s.nextInt();
            int x = s.nextInt();
            int k = s.nextInt();
            int c=0;
            while (n > 0){
                n = n - x;
                c+=1;
            }
            System.out.println(k*c);
    }
    } import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
            int n = s.nextInt();
            int x = s.nextInt();
            int k = s.nextInt();
            int c=0;
            while (n > 0){
                n = n - x;
                c+=1;
            }
            System.out.println(k*c);
    }
    } Main public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
            int n = s.nextInt();
            int x = s.nextInt();
            int k = s.nextInt();
            int c=0;
            while (n > 0){
                n = n - x;
                c+=1;
            }
            System.out.println(k*c);
    } main {
        Scanner s = new Scanner(System.in);
            int n = s.nextInt();
            int x = s.nextInt();
            int k = s.nextInt();
            int c=0;
            while (n > 0){
                n = n - x;
                c+=1;
            }
            System.out.println(k*c);
    } Scanner s = new Scanner(System.in); s new Scanner(System.in) int n = s.nextInt(); n s.nextInt() s.nextInt s int x = s.nextInt(); x s.nextInt() s.nextInt s int k = s.nextInt(); k s.nextInt() s.nextInt s int c=0; c 0 while (n > 0){
                n = n - x;
                c+=1;
            } n > 0 n 0 {
                n = n - x;
                c+=1;
            } n = n - x n n - x n x c+=1 c 1 System.out.println(k*c) System.out.println System.out System System.out k*c k c String[] args args public class Main {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
            int n = s.nextInt();
            int x = s.nextInt();
            int k = s.nextInt();
            int c=0;
            while (n > 0){
                n = n - x;
                c+=1;
            }
            System.out.println(k*c);
    }
    } public class Main {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
            int n = s.nextInt();
            int x = s.nextInt();
            int k = s.nextInt();
            int c=0;
            while (n > 0){
                n = n - x;
                c+=1;
            }
            System.out.println(k*c);
    }
    } Main
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
            int n = s.nextInt();
            int x = s.nextInt();
            int k = s.nextInt();
            int c=0;
            while (n > 0){
                n = n - x;
                c+=1;
            }
            System.out.println(k*c);
    }
    }
