//答案：

#include <bits/stdc++.h>
using namespace std;
int n,a,i = 1,b;
bool l = false;
int main(){
	cin >> n;
	while(!l){
		a = i;
		for(int j = 1 ; j <= n ; j++){
			b = a - 1;
			if(a % n != 1 || b <= 0){
				l = false;
				break;
			}
			a = (a - 1) / n * (n - 1);
			l = true;
		}
		i++;
	}
	i--;
	cout << i << endl;
	return 0;
}