package cn.ifiv5.IP;
import java.io.*;
 
/**
 *
 * @author Arno
 */
public class Main {
    public static void main(String[] args) {
        new Main().go();
    }
    
    /**
     * 程序主要逻辑
     */
 
    public void go() {
        String IP = null;
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        try{
            IP = br.readLine();
        }catch(IOException ex){
            ex.printStackTrace();
        }
        
        IP = IP.replace(" ", "");
        String []temp = IP.split("/");
        String []sIP = temp[0].split("\\.");
        
        /**
         * 判断输入格式是否正确
         */
        
        if(temp.length < 2)
        {
         System.out.println("对不起，输入格式错误");
         System.exit(0);
        }
        
        
        int Mask = Integer.parseInt(temp[1]);
        int []ip = new int[4];
    
        for(int i=0;i<sIP.length;i++)
        {
         ip[i] = Integer.parseInt(sIP[i]);
        }
        
        /**
         * IP地址各段不能大于255
         */
        
        for(int i=0; i < 4; i++)
        {
         if(ip[i] > 255)
         {
          System.out.println("对不起，IP输入错误");
          System.exit(0);
         }
        }
        
        /**
         * 判断IP地址所属分类
         */
        
        int ipclass = 0;
        
        if(ip[0] < 127){
         ipclass = 1;
        }else if(ip[0] < 192){
         ipclass = 2;
        }else if(ip[0] < 224){
         ipclass = 3;
        }
        
        /**
         * 判断子网掩码是否输入正确
         */
        
        if(Mask < 8 * ipclass)
        {
         System.out.println("对不起，子网掩码输入错误");
         System.exit(0);
        }
        
        int b=0;
        int a = Mask%8;
        
        b=Mask/8;
        
        StringBuffer sb = new StringBuffer();
        
        for(int i=0;i<a;i++)
         sb.append('1');
        for(int i=0;i<8-a;i++)
         sb.append('0');
        
        int end =Integer.parseInt(sb.toString(),2);
       
        ip[b] = ip[b]&end;
        for(int i=b+1;i<4;i++)
         ip[i] = 0;
        
        for(int i=0;i<4;i++)
        {
         System.out.print(ip[i]);
         if(i!=3)
          System.out.print(".");
        }
        
        
    }
}