#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n=1,x;
	float s;
	cin>>x;
	while(s<x){
		s+=1.0/n*1.0;
		n++;
	}
	cout<<n-1;	
	return 0;
}
/**************************************************************
	Problem: 1078
	User: houshanglin
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/