#include<iostream>
#include<string>
using namespace std;
int main()
{
    string username;
    int age;
    
    getline(cin,username);
    cin>>age;
    try
    {
        if(username.lengh()<3)
        {
            throw "Invalid username";
        }
        if(age<18||age>100)
        {
            throw "Invalid age;"
        }
        cout<<"Registration successful";
    }
    catch(canst char* msg)
    {
        cout<<msg;
    }
    return 0;
}