#include <iostream>
#include <iomanip>
using namespace std;

int main(){//P1035 [NOIP2002 普及组] 级数求和
	int k;
	cin >> k;
	int n = 1;
	double sum = 1;

	while(sum <= k){
		sum = sum + (double)1 / n;
		n++;
	} 
	cout << n;
	
	return 0;
}