#include<iostrea>
#include<string>
using namespace std;
int main(){
    string username;
    int age;
    if(!(cin>>username>>age)) return 0;
    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;
}