#include<iostream>
#include<string>
using namespace std;

int mian() {
    string username;{
        int age;
        getline(cin,username);
        cin>>age;
        
        if(username.length()<3) {
            cout<<"invalid username"<<endl;
        }
        else if(age<18||age>100){
            cout<<"invalid age"<<endl;
        }
        else{
            cout<<"registration successful"<<endl;
        }
    }
    return 0;
}