#include #include #include using namespace std; int main() {

int n;
0 <= n <= 25;
cin >> n;
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";
}

return 0;

}