#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n=0,x;
	float s;
	cin>>x;
	while(s<=x){
		n++;
		s+=1.00*1/n;
	}
	cout<<n;
	return 0;
}

/**************************************************************
	Problem: 1078
	User: zzz
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/