import java.util.*;

public class Main {
    public static void main(String[] args) 
    {
       Scanner input=new Scanner(System.in);
       String s=input.nextLine();
       int f=1;
       if(s.charAt(0)=='@'||s.charAt=='.')
       f=0;
       int t=0;
       for(int i=0;i<s.length();i++)
       {
        if(s.charAt(i)=='@')
        {
            t=1;
            break;
        }
       }
       if(t==0)
       f=0;
       String ss=s.substring(s.length()-4,s.length());
       if(!ss.equals(".com"))
       f=0;
       if(f==0)
       System.out.println("邮箱格式不合法");
       else
       System.out.println("邮箱格式合法");

        
        
    }
}