import java.util.*;
import java.io.*;

public class Main{

static BufferedReader s1;
static BufferedWriter out;
static String read() throws IOException{String line="";while(line.length()==0){line=s1.readLine();continue;}return line;}
static int int_v (String s1){return Integer.parseInt(s1);}
static long long_v(String s1){return Long.parseLong(s1);}
static int[] int_arr() throws IOException{String[] a=read().split("\\s+");int[] b=new int[a.length];for(int i=0;i<a.length;i++){b[i]=int_v(a[i]);}return b;}
static long[] long_arr() throws IOException{String[] a=read().split("\\s+");long[] b=new long[a.length];for(int i=0;i<a.length;i++){b[i]=long_v(a[i]);}return b;}
static void assign(){s1=new BufferedReader(new InputStreamReader(System.in));out=new BufferedWriter(new OutputStreamWriter(System.out));}
static int Modpow(int a,int p,int m){int res=1;while(p>0){if((p&1)!=0){res=(res*a)%m;}p >>=1;a=(a*a)%m;}return res;}
//......................................@uthor_Alx..............................................
static long mod=(long)1e9+7;
public static void main(String[] args) throws  IOException{
                assign();
                int[] a=int_arr();
                int r=(int)Math.ceil((double)a[0]/a[1])*a[2];
                out.write(r+"\n");            
                out.flush();

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

static BufferedReader s1;
static BufferedWriter out;
static String read() throws IOException{String line="";while(line.length()==0){line=s1.readLine();continue;}return line;}
static int int_v (String s1){return Integer.parseInt(s1);}
static long long_v(String s1){return Long.parseLong(s1);}
static int[] int_arr() throws IOException{String[] a=read().split("\\s+");int[] b=new int[a.length];for(int i=0;i<a.length;i++){b[i]=int_v(a[i]);}return b;}
static long[] long_arr() throws IOException{String[] a=read().split("\\s+");long[] b=new long[a.length];for(int i=0;i<a.length;i++){b[i]=long_v(a[i]);}return b;}
static void assign(){s1=new BufferedReader(new InputStreamReader(System.in));out=new BufferedWriter(new OutputStreamWriter(System.out));}
static int Modpow(int a,int p,int m){int res=1;while(p>0){if((p&1)!=0){res=(res*a)%m;}p >>=1;a=(a*a)%m;}return res;}
//......................................@uthor_Alx..............................................
static long mod=(long)1e9+7;
public static void main(String[] args) throws  IOException{
                assign();
                int[] a=int_arr();
                int r=(int)Math.ceil((double)a[0]/a[1])*a[2];
                out.write(r+"\n");            
                out.flush();

    }
} Main static BufferedReader s1; s1 static BufferedWriter out; out //......................................@uthor_Alx..............................................
static long mod=(long)1e9+7; mod (long)1e9+7 (long)1e9 7 static String read() throws IOException{String line="";while(line.length()==0){line=s1.readLine();continue;}return line;} read {String line="";while(line.length()==0){line=s1.readLine();continue;}return line;} String line=""; line "" while(line.length()==0){line=s1.readLine();continue;} line.length()==0 line.length() line.length line 0 {line=s1.readLine();continue;} line=s1.readLine() line s1.readLine() s1.readLine s1 continue; return line; line static int int_v (String s1){return Integer.parseInt(s1);} int_v {return Integer.parseInt(s1);} return Integer.parseInt(s1); Integer.parseInt(s1) Integer.parseInt Integer s1 String s1 s1 static long long_v(String s1){return Long.parseLong(s1);} long_v {return Long.parseLong(s1);} return Long.parseLong(s1); Long.parseLong(s1) Long.parseLong Long s1 String s1 s1 static int[] int_arr() throws IOException{String[] a=read().split("\\s+");int[] b=new int[a.length];for(int i=0;i<a.length;i++){b[i]=int_v(a[i]);}return b;} int_arr {String[] a=read().split("\\s+");int[] b=new int[a.length];for(int i=0;i<a.length;i++){b[i]=int_v(a[i]);}return b;} String[] a=read().split("\\s+"); a read().split("\\s+") read().split read() read "\\s+" int[] b=new int[a.length]; b new int[a.length] a.length a a.length for(int i=0;i<a.length;i++){b[i]=int_v(a[i]);} int i=0; int i=0; i 0 i<a.length i a.length a a.length i++ i++ i {b[i]=int_v(a[i]);} {b[i]=int_v(a[i]);} b[i]=int_v(a[i]) b[i] b i int_v(a[i]) int_v a[i] a i return b; b static long[] long_arr() throws IOException{String[] a=read().split("\\s+");long[] b=new long[a.length];for(int i=0;i<a.length;i++){b[i]=long_v(a[i]);}return b;} long_arr {String[] a=read().split("\\s+");long[] b=new long[a.length];for(int i=0;i<a.length;i++){b[i]=long_v(a[i]);}return b;} String[] a=read().split("\\s+"); a read().split("\\s+") read().split read() read "\\s+" long[] b=new long[a.length]; b new long[a.length] a.length a a.length for(int i=0;i<a.length;i++){b[i]=long_v(a[i]);} int i=0; int i=0; i 0 i<a.length i a.length a a.length i++ i++ i {b[i]=long_v(a[i]);} {b[i]=long_v(a[i]);} b[i]=long_v(a[i]) b[i] b i long_v(a[i]) long_v a[i] a i return b; b static void assign(){s1=new BufferedReader(new InputStreamReader(System.in));out=new BufferedWriter(new OutputStreamWriter(System.out));} assign {s1=new BufferedReader(new InputStreamReader(System.in));out=new BufferedWriter(new OutputStreamWriter(System.out));} s1=new BufferedReader(new InputStreamReader(System.in)) s1 new BufferedReader(new InputStreamReader(System.in)) out=new BufferedWriter(new OutputStreamWriter(System.out)) out new BufferedWriter(new OutputStreamWriter(System.out)) static int Modpow(int a,int p,int m){int res=1;while(p>0){if((p&1)!=0){res=(res*a)%m;}p >>=1;a=(a*a)%m;}return res;} Modpow {int res=1;while(p>0){if((p&1)!=0){res=(res*a)%m;}p >>=1;a=(a*a)%m;}return res;} int res=1; res 1 while(p>0){if((p&1)!=0){res=(res*a)%m;}p >>=1;a=(a*a)%m;} p>0 p 0 {if((p&1)!=0){res=(res*a)%m;}p >>=1;a=(a*a)%m;} if((p&1)!=0){res=(res*a)%m;} (p&1)!=0 (p&1) p 1 0 {res=(res*a)%m;} res=(res*a)%m res (res*a)%m (res*a) res a m p >>=1 p 1 a=(a*a)%m a (a*a)%m (a*a) a a m return res; res int a a int p p int m m public static void main(String[] args) throws  IOException{
                assign();
                int[] a=int_arr();
                int r=(int)Math.ceil((double)a[0]/a[1])*a[2];
                out.write(r+"\n");            
                out.flush();

    } main {
                assign();
                int[] a=int_arr();
                int r=(int)Math.ceil((double)a[0]/a[1])*a[2];
                out.write(r+"\n");            
                out.flush();

    } assign() assign int[] a=int_arr(); a int_arr() int_arr int r=(int)Math.ceil((double)a[0]/a[1])*a[2]; r (int)Math.ceil((double)a[0]/a[1])*a[2] (int)Math.ceil((double)a[0]/a[1]) Math.ceil Math (double)a[0]/a[1] (double)a[0] a 0 a[1] a 1 a[2] a 2 out.write(r+"\n") out.write out r+"\n" r "\n" out.flush() out.flush out String[] args args public class Main{

static BufferedReader s1;
static BufferedWriter out;
static String read() throws IOException{String line="";while(line.length()==0){line=s1.readLine();continue;}return line;}
static int int_v (String s1){return Integer.parseInt(s1);}
static long long_v(String s1){return Long.parseLong(s1);}
static int[] int_arr() throws IOException{String[] a=read().split("\\s+");int[] b=new int[a.length];for(int i=0;i<a.length;i++){b[i]=int_v(a[i]);}return b;}
static long[] long_arr() throws IOException{String[] a=read().split("\\s+");long[] b=new long[a.length];for(int i=0;i<a.length;i++){b[i]=long_v(a[i]);}return b;}
static void assign(){s1=new BufferedReader(new InputStreamReader(System.in));out=new BufferedWriter(new OutputStreamWriter(System.out));}
static int Modpow(int a,int p,int m){int res=1;while(p>0){if((p&1)!=0){res=(res*a)%m;}p >>=1;a=(a*a)%m;}return res;}
//......................................@uthor_Alx..............................................
static long mod=(long)1e9+7;
public static void main(String[] args) throws  IOException{
                assign();
                int[] a=int_arr();
                int r=(int)Math.ceil((double)a[0]/a[1])*a[2];
                out.write(r+"\n");            
                out.flush();

    }
} public class Main{

static BufferedReader s1;
static BufferedWriter out;
static String read() throws IOException{String line="";while(line.length()==0){line=s1.readLine();continue;}return line;}
static int int_v (String s1){return Integer.parseInt(s1);}
static long long_v(String s1){return Long.parseLong(s1);}
static int[] int_arr() throws IOException{String[] a=read().split("\\s+");int[] b=new int[a.length];for(int i=0;i<a.length;i++){b[i]=int_v(a[i]);}return b;}
static long[] long_arr() throws IOException{String[] a=read().split("\\s+");long[] b=new long[a.length];for(int i=0;i<a.length;i++){b[i]=long_v(a[i]);}return b;}
static void assign(){s1=new BufferedReader(new InputStreamReader(System.in));out=new BufferedWriter(new OutputStreamWriter(System.out));}
static int Modpow(int a,int p,int m){int res=1;while(p>0){if((p&1)!=0){res=(res*a)%m;}p >>=1;a=(a*a)%m;}return res;}
//......................................@uthor_Alx..............................................
static long mod=(long)1e9+7;
public static void main(String[] args) throws  IOException{
                assign();
                int[] a=int_arr();
                int r=(int)Math.ceil((double)a[0]/a[1])*a[2];
                out.write(r+"\n");            
                out.flush();

    }
} Main
import java.util.*;
import java.io.*;

public class Main{

static BufferedReader s1;
static BufferedWriter out;
static String read() throws IOException{String line="";while(line.length()==0){line=s1.readLine();continue;}return line;}
static int int_v (String s1){return Integer.parseInt(s1);}
static long long_v(String s1){return Long.parseLong(s1);}
static int[] int_arr() throws IOException{String[] a=read().split("\\s+");int[] b=new int[a.length];for(int i=0;i<a.length;i++){b[i]=int_v(a[i]);}return b;}
static long[] long_arr() throws IOException{String[] a=read().split("\\s+");long[] b=new long[a.length];for(int i=0;i<a.length;i++){b[i]=long_v(a[i]);}return b;}
static void assign(){s1=new BufferedReader(new InputStreamReader(System.in));out=new BufferedWriter(new OutputStreamWriter(System.out));}
static int Modpow(int a,int p,int m){int res=1;while(p>0){if((p&1)!=0){res=(res*a)%m;}p >>=1;a=(a*a)%m;}return res;}
//......................................@uthor_Alx..............................................
static long mod=(long)1e9+7;
public static void main(String[] args) throws  IOException{
                assign();
                int[] a=int_arr();
                int r=(int)Math.ceil((double)a[0]/a[1])*a[2];
                out.write(r+"\n");            
                out.flush();

    }
}