#include<bits/stdc++.h>

using namespace std;
 
typedef long long int ll;
typedef long double ld;
#define f first
#define s second
#define pb push_back
#define pii pair<int, int>

 
const int N = 2e5 + 100;
const int inf = 1e9;
const ll mod =  998244353;
const ld eq = 1e-18;



int main()
{
	ld p;
	cin >> p;
	p = 1-p;	
	ld P = p;
	int n = 1;
	ld ans = 1; 
	for(int i = 2; i <= 16; i++)
	{
		P = P*p;
		ld E = (P + i*(1-P))/ld(i);
		//cout << fixed << setprecision(20) << P << ' ' << E << endl;
	
		//cout << ans - E << endl;
		if(ans - E > eq)
		{
			ans = E;
			n = i;
		}
	}
	cout << n << endl;
	
    return 0;
}