import java.util.Scanner;

class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
      
      	int total = sc.nextInt();
      	int once = sc.nextInt();
      	int time = sc.nextInt();
      	int count = 0;
      
		while(total > 0) {
        	total -= once;
      		count++;    	
        }
      	System.out.println(count * time);
    
    
    }
} import java.util.Scanner; Scanner java.util class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
      
      	int total = sc.nextInt();
      	int once = sc.nextInt();
      	int time = sc.nextInt();
      	int count = 0;
      
		while(total > 0) {
        	total -= once;
      		count++;    	
        }
      	System.out.println(count * time);
    
    
    }
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
      
      	int total = sc.nextInt();
      	int once = sc.nextInt();
      	int time = sc.nextInt();
      	int count = 0;
      
		while(total > 0) {
        	total -= once;
      		count++;    	
        }
      	System.out.println(count * time);
    
    
    } main {
		Scanner sc = new Scanner(System.in);
      
      	int total = sc.nextInt();
      	int once = sc.nextInt();
      	int time = sc.nextInt();
      	int count = 0;
      
		while(total > 0) {
        	total -= once;
      		count++;    	
        }
      	System.out.println(count * time);
    
    
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int total = sc.nextInt(); total sc.nextInt() sc.nextInt sc int once = sc.nextInt(); once sc.nextInt() sc.nextInt sc int time = sc.nextInt(); time sc.nextInt() sc.nextInt sc int count = 0; count 0 while(total > 0) {
        	total -= once;
      		count++;    	
        } total > 0 total 0 {
        	total -= once;
      		count++;    	
        } total -= once total once count++ count System.out.println(count * time) System.out.println System.out System System.out count * time count time String[] args args
import java.util.Scanner;

class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
      
      	int total = sc.nextInt();
      	int once = sc.nextInt();
      	int time = sc.nextInt();
      	int count = 0;
      
		while(total > 0) {
        	total -= once;
      		count++;    	
        }
      	System.out.println(count * time);
    
    
    }
}