import java.util.*;


public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String line = sc.nextLine();
        String[] lines = line.split(" ", 0);

        int num = Integer.parseInt(lines[0]);
        int make = Integer.parseInt(lines[1]);
        int time = Integer.parseInt(lines[2]);

        int ret = time * (int)(Math.ceil(1.0 * num / make));
        
        System.out.println(ret);
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String line = sc.nextLine();
        String[] lines = line.split(" ", 0);

        int num = Integer.parseInt(lines[0]);
        int make = Integer.parseInt(lines[1]);
        int time = Integer.parseInt(lines[2]);

        int ret = time * (int)(Math.ceil(1.0 * num / make));
        
        System.out.println(ret);
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String line = sc.nextLine();
        String[] lines = line.split(" ", 0);

        int num = Integer.parseInt(lines[0]);
        int make = Integer.parseInt(lines[1]);
        int time = Integer.parseInt(lines[2]);

        int ret = time * (int)(Math.ceil(1.0 * num / make));
        
        System.out.println(ret);
    } main {
        Scanner sc = new Scanner(System.in);
        String line = sc.nextLine();
        String[] lines = line.split(" ", 0);

        int num = Integer.parseInt(lines[0]);
        int make = Integer.parseInt(lines[1]);
        int time = Integer.parseInt(lines[2]);

        int ret = time * (int)(Math.ceil(1.0 * num / make));
        
        System.out.println(ret);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String line = sc.nextLine(); line sc.nextLine() sc.nextLine sc String[] lines = line.split(" ", 0); lines line.split(" ", 0) line.split line " " 0 int num = Integer.parseInt(lines[0]); num Integer.parseInt(lines[0]) Integer.parseInt Integer lines[0] lines 0 int make = Integer.parseInt(lines[1]); make Integer.parseInt(lines[1]) Integer.parseInt Integer lines[1] lines 1 int time = Integer.parseInt(lines[2]); time Integer.parseInt(lines[2]) Integer.parseInt Integer lines[2] lines 2 int ret = time * (int)(Math.ceil(1.0 * num / make)); ret time * (int)(Math.ceil(1.0 * num / make)) time (int)(Math.ceil(1.0 * num / make)) Math.ceil Math 1.0 * num / make 1.0 * num 1.0 num make System.out.println(ret) System.out.println System.out System System.out ret String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String line = sc.nextLine();
        String[] lines = line.split(" ", 0);

        int num = Integer.parseInt(lines[0]);
        int make = Integer.parseInt(lines[1]);
        int time = Integer.parseInt(lines[2]);

        int ret = time * (int)(Math.ceil(1.0 * num / make));
        
        System.out.println(ret);
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String line = sc.nextLine();
        String[] lines = line.split(" ", 0);

        int num = Integer.parseInt(lines[0]);
        int make = Integer.parseInt(lines[1]);
        int time = Integer.parseInt(lines[2]);

        int ret = time * (int)(Math.ceil(1.0 * num / make));
        
        System.out.println(ret);
    }
} Main
import java.util.*;


public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String line = sc.nextLine();
        String[] lines = line.split(" ", 0);

        int num = Integer.parseInt(lines[0]);
        int make = Integer.parseInt(lines[1]);
        int time = Integer.parseInt(lines[2]);

        int ret = time * (int)(Math.ceil(1.0 * num / make));
        
        System.out.println(ret);
    }
}
