import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    String n = scan.next();
    String x = scan.next();
    String t = scan.next();
    int nn = Integer.parseInt(n);
    int xx = Integer.parseInt(x);
    int tt = Integer.parseInt(t);
    
    int times;
    if (nn % xx == 0) {
      times = nn / xx;
    } else {
      times = (nn / xx) + 1;
    }
    int answer = tt * times;
    
    System.out.println(answer);
  }
} import java.util.Scanner; Scanner java.util public class Main {
  public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    String n = scan.next();
    String x = scan.next();
    String t = scan.next();
    int nn = Integer.parseInt(n);
    int xx = Integer.parseInt(x);
    int tt = Integer.parseInt(t);
    
    int times;
    if (nn % xx == 0) {
      times = nn / xx;
    } else {
      times = (nn / xx) + 1;
    }
    int answer = tt * times;
    
    System.out.println(answer);
  }
} Main public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    String n = scan.next();
    String x = scan.next();
    String t = scan.next();
    int nn = Integer.parseInt(n);
    int xx = Integer.parseInt(x);
    int tt = Integer.parseInt(t);
    
    int times;
    if (nn % xx == 0) {
      times = nn / xx;
    } else {
      times = (nn / xx) + 1;
    }
    int answer = tt * times;
    
    System.out.println(answer);
  } main {
    Scanner scan = new Scanner(System.in);
    String n = scan.next();
    String x = scan.next();
    String t = scan.next();
    int nn = Integer.parseInt(n);
    int xx = Integer.parseInt(x);
    int tt = Integer.parseInt(t);
    
    int times;
    if (nn % xx == 0) {
      times = nn / xx;
    } else {
      times = (nn / xx) + 1;
    }
    int answer = tt * times;
    
    System.out.println(answer);
  } Scanner scan = new Scanner(System.in); scan new Scanner(System.in) String n = scan.next(); n scan.next() scan.next scan String x = scan.next(); x scan.next() scan.next scan String t = scan.next(); t scan.next() scan.next scan int nn = Integer.parseInt(n); nn Integer.parseInt(n) Integer.parseInt Integer n int xx = Integer.parseInt(x); xx Integer.parseInt(x) Integer.parseInt Integer x int tt = Integer.parseInt(t); tt Integer.parseInt(t) Integer.parseInt Integer t int times; times if (nn % xx == 0) {
      times = nn / xx;
    } else {
      times = (nn / xx) + 1;
    } nn % xx == 0 nn % xx nn xx 0 {
      times = nn / xx;
    } times = nn / xx times nn / xx nn xx {
      times = (nn / xx) + 1;
    } times = (nn / xx) + 1 times (nn / xx) + 1 (nn / xx) nn xx 1 int answer = tt * times; answer tt * times tt times System.out.println(answer) System.out.println System.out System System.out answer String[] args args public class Main {
  public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    String n = scan.next();
    String x = scan.next();
    String t = scan.next();
    int nn = Integer.parseInt(n);
    int xx = Integer.parseInt(x);
    int tt = Integer.parseInt(t);
    
    int times;
    if (nn % xx == 0) {
      times = nn / xx;
    } else {
      times = (nn / xx) + 1;
    }
    int answer = tt * times;
    
    System.out.println(answer);
  }
} public class Main {
  public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    String n = scan.next();
    String x = scan.next();
    String t = scan.next();
    int nn = Integer.parseInt(n);
    int xx = Integer.parseInt(x);
    int tt = Integer.parseInt(t);
    
    int times;
    if (nn % xx == 0) {
      times = nn / xx;
    } else {
      times = (nn / xx) + 1;
    }
    int answer = tt * times;
    
    System.out.println(answer);
  }
} Main
import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    String n = scan.next();
    String x = scan.next();
    String t = scan.next();
    int nn = Integer.parseInt(n);
    int xx = Integer.parseInt(x);
    int tt = Integer.parseInt(t);
    
    int times;
    if (nn % xx == 0) {
      times = nn / xx;
    } else {
      times = (nn / xx) + 1;
    }
    int answer = tt * times;
    
    System.out.println(answer);
  }
}