import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

    public static void main(String[] args) {
        InputStreamReader in = new InputStreamReader(System.in);
        BufferedReader bufferedReader = new BufferedReader(in);
        try {

            String input = bufferedReader.readLine();
            String[] inputsArrays = input.split(" ");

            int N = Integer.parseInt(inputsArrays[0]);
            int X = Integer.parseInt(inputsArrays[1]);
            int T = Integer.parseInt(inputsArrays[2]);

            int timeTaken = 0;
            while (N>0){
                timeTaken += T;
                N -=  X;
            }
            System.out.println(timeTaken);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
} import java.io.BufferedReader; BufferedReader java.io import java.io.IOException; IOException java.io import java.io.InputStreamReader; InputStreamReader java.io public class Main {

    public static void main(String[] args) {
        InputStreamReader in = new InputStreamReader(System.in);
        BufferedReader bufferedReader = new BufferedReader(in);
        try {

            String input = bufferedReader.readLine();
            String[] inputsArrays = input.split(" ");

            int N = Integer.parseInt(inputsArrays[0]);
            int X = Integer.parseInt(inputsArrays[1]);
            int T = Integer.parseInt(inputsArrays[2]);

            int timeTaken = 0;
            while (N>0){
                timeTaken += T;
                N -=  X;
            }
            System.out.println(timeTaken);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
} Main public static void main(String[] args) {
        InputStreamReader in = new InputStreamReader(System.in);
        BufferedReader bufferedReader = new BufferedReader(in);
        try {

            String input = bufferedReader.readLine();
            String[] inputsArrays = input.split(" ");

            int N = Integer.parseInt(inputsArrays[0]);
            int X = Integer.parseInt(inputsArrays[1]);
            int T = Integer.parseInt(inputsArrays[2]);

            int timeTaken = 0;
            while (N>0){
                timeTaken += T;
                N -=  X;
            }
            System.out.println(timeTaken);
        } catch (IOException e) {
            e.printStackTrace();
        }
    } main {
        InputStreamReader in = new InputStreamReader(System.in);
        BufferedReader bufferedReader = new BufferedReader(in);
        try {

            String input = bufferedReader.readLine();
            String[] inputsArrays = input.split(" ");

            int N = Integer.parseInt(inputsArrays[0]);
            int X = Integer.parseInt(inputsArrays[1]);
            int T = Integer.parseInt(inputsArrays[2]);

            int timeTaken = 0;
            while (N>0){
                timeTaken += T;
                N -=  X;
            }
            System.out.println(timeTaken);
        } catch (IOException e) {
            e.printStackTrace();
        }
    } InputStreamReader in = new InputStreamReader(System.in); in new InputStreamReader(System.in) BufferedReader bufferedReader = new BufferedReader(in); bufferedReader new BufferedReader(in) try {

            String input = bufferedReader.readLine();
            String[] inputsArrays = input.split(" ");

            int N = Integer.parseInt(inputsArrays[0]);
            int X = Integer.parseInt(inputsArrays[1]);
            int T = Integer.parseInt(inputsArrays[2]);

            int timeTaken = 0;
            while (N>0){
                timeTaken += T;
                N -=  X;
            }
            System.out.println(timeTaken);
        } catch (IOException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } IOException e {
            e.printStackTrace();
        } e.printStackTrace() e.printStackTrace e {

            String input = bufferedReader.readLine();
            String[] inputsArrays = input.split(" ");

            int N = Integer.parseInt(inputsArrays[0]);
            int X = Integer.parseInt(inputsArrays[1]);
            int T = Integer.parseInt(inputsArrays[2]);

            int timeTaken = 0;
            while (N>0){
                timeTaken += T;
                N -=  X;
            }
            System.out.println(timeTaken);
        } String input = bufferedReader.readLine(); input bufferedReader.readLine() bufferedReader.readLine bufferedReader String[] inputsArrays = input.split(" "); inputsArrays input.split(" ") input.split input " " int N = Integer.parseInt(inputsArrays[0]); N Integer.parseInt(inputsArrays[0]) Integer.parseInt Integer inputsArrays[0] inputsArrays 0 int X = Integer.parseInt(inputsArrays[1]); X Integer.parseInt(inputsArrays[1]) Integer.parseInt Integer inputsArrays[1] inputsArrays 1 int T = Integer.parseInt(inputsArrays[2]); T Integer.parseInt(inputsArrays[2]) Integer.parseInt Integer inputsArrays[2] inputsArrays 2 int timeTaken = 0; timeTaken 0 while (N>0){
                timeTaken += T;
                N -=  X;
            } N>0 N 0 {
                timeTaken += T;
                N -=  X;
            } timeTaken += T timeTaken T N -=  X N X System.out.println(timeTaken) System.out.println System.out System System.out timeTaken String[] args args public class Main {

    public static void main(String[] args) {
        InputStreamReader in = new InputStreamReader(System.in);
        BufferedReader bufferedReader = new BufferedReader(in);
        try {

            String input = bufferedReader.readLine();
            String[] inputsArrays = input.split(" ");

            int N = Integer.parseInt(inputsArrays[0]);
            int X = Integer.parseInt(inputsArrays[1]);
            int T = Integer.parseInt(inputsArrays[2]);

            int timeTaken = 0;
            while (N>0){
                timeTaken += T;
                N -=  X;
            }
            System.out.println(timeTaken);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
} public class Main {

    public static void main(String[] args) {
        InputStreamReader in = new InputStreamReader(System.in);
        BufferedReader bufferedReader = new BufferedReader(in);
        try {

            String input = bufferedReader.readLine();
            String[] inputsArrays = input.split(" ");

            int N = Integer.parseInt(inputsArrays[0]);
            int X = Integer.parseInt(inputsArrays[1]);
            int T = Integer.parseInt(inputsArrays[2]);

            int timeTaken = 0;
            while (N>0){
                timeTaken += T;
                N -=  X;
            }
            System.out.println(timeTaken);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
} Main
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

    public static void main(String[] args) {
        InputStreamReader in = new InputStreamReader(System.in);
        BufferedReader bufferedReader = new BufferedReader(in);
        try {

            String input = bufferedReader.readLine();
            String[] inputsArrays = input.split(" ");

            int N = Integer.parseInt(inputsArrays[0]);
            int X = Integer.parseInt(inputsArrays[1]);
            int T = Integer.parseInt(inputsArrays[2]);

            int timeTaken = 0;
            while (N>0){
                timeTaken += T;
                N -=  X;
            }
            System.out.println(timeTaken);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}
