public class JieCheng {
public static void main(String[] args){
System.out.println(JieCheng.digui(31));
}
public static long digui(int n){
if(n <= 1) return 1;
else return digui(n-1)*n;
}
}

public class JieCheng {
public static void main(String[] args){
System.out.println(JieCheng.digui(31));
}
public static long digui(int n){
if(n <= 1) return 1;
else return digui(n-1)*n;
}
}