import java.util.*;

public class Main {


	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		int c = sc.nextInt();
		if(a%b==0) {
			System.out.println(a/b*c);
		}else {
			System.out.println((a/b+1)*c);
		}

	}


} import java.util.*; util.* java public class Main {


	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		int c = sc.nextInt();
		if(a%b==0) {
			System.out.println(a/b*c);
		}else {
			System.out.println((a/b+1)*c);
		}

	}


} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		int c = sc.nextInt();
		if(a%b==0) {
			System.out.println(a/b*c);
		}else {
			System.out.println((a/b+1)*c);
		}

	} main {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		int c = sc.nextInt();
		if(a%b==0) {
			System.out.println(a/b*c);
		}else {
			System.out.println((a/b+1)*c);
		}

	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int a = sc.nextInt(); a sc.nextInt() sc.nextInt sc int b = sc.nextInt(); b sc.nextInt() sc.nextInt sc int c = sc.nextInt(); c sc.nextInt() sc.nextInt sc if(a%b==0) {
			System.out.println(a/b*c);
		}else {
			System.out.println((a/b+1)*c);
		} a%b==0 a%b a b 0 {
			System.out.println(a/b*c);
		} System.out.println(a/b*c) System.out.println System.out System System.out a/b*c a/b a b c {
			System.out.println((a/b+1)*c);
		} System.out.println((a/b+1)*c) System.out.println System.out System System.out (a/b+1)*c (a/b+1) a/b a b 1 c String[] args args public class Main {


	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		int c = sc.nextInt();
		if(a%b==0) {
			System.out.println(a/b*c);
		}else {
			System.out.println((a/b+1)*c);
		}

	}


} public class Main {


	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		int c = sc.nextInt();
		if(a%b==0) {
			System.out.println(a/b*c);
		}else {
			System.out.println((a/b+1)*c);
		}

	}


} Main
import java.util.*;

public class Main {


	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		int c = sc.nextInt();
		if(a%b==0) {
			System.out.println(a/b*c);
		}else {
			System.out.println((a/b+1)*c);
		}

	}


}
