#include<bits/stdc++.h> using namespace std; int main() { int n; cin>>n; n<25; if(n>=0 && n<=3) { cout<<"infant"; } else if(n>=4 && n<=12) { cout<<"child"; } else if(n>=13 && n<=18) { cout<<"youngster"; } else if(n>=19 && n<=25) { cout<<"youth"; } }