Poj Solution 3006

http://poj.org/problem?id=3006

//* @author popop0p0popo
import java.util.*;
import java.io.*;

public class Main{
 public static void main(String[] args){
  Scanner scanner=new Scanner(new BufferedReader(new InputStreamReader(System.in)));
    while (true){
        int a=scanner.nextInt();
        int d=scanner.nextInt();
        int n=scanner.nextInt();
        if (a+d+n==0){
            break;
        }
        int index=0;
        int i=0;
        while (index< n){
            if (isZh(a+d*i)){
                index++;
            }
            i++;
        }
        System.out.println(a+d*(i-1));
    }
  }

    public static boolean isZh(int p){
        if (p==1){
            return false;
        }
        if (p==2){
            return true;
        }
        if (p%2==0){
            return false;
        }
        for (int i=3;i*i<=p ;i=i+2 ){
            if (p%i==0){
                return false;
            }
        }
        return true;
    }
}