#include <bits/stdc++.h>
#define REP(i,n,N) for(int i=(n);i<(int) N;i++)
#define RREP(i,n,N) for(int i=N-1;i>=(int) n;i--)
#define p(s) cout<<(s)<<endl
using namespace std;

int N;
string D = "0.1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991";

string sum(string a, string b) {
	int da = a.find('.');
	int db = b.find('.');

	if (da < db)
		REP(i, 0, db - da) a = "0" + a;
	else if(da > db)
		REP(i, 0, da - db) b = "0" + b;

	int na = a.length();
	int nb = b.length();
	int n = max(na, nb);

	if (na < nb)
		REP(i, 0, nb - na) a = a + "0";
	else if (na > nb)
		REP(i, 0, na - nb) b = b + "0";

	string ret = "";
	int z = 0;
	RREP(i, 0, n ) {
		if (a[i] == '.') {
			ret = "." + ret;
			continue;
		}
		int aa = a[i] - '0';
		int bb = b[i] - '0';
		char c = '0';
		int cc = (aa + bb + z) % 10;
		c += cc;
		z = (aa + bb + z) / 10;
		ret = c + ret;
	}
	if (z != 0) {
		char c = '0' + z;
		ret = c + ret;
	}
	return ret;
}

int main() {
	cin >> N;
	string ans = D;
	REP(i, 1, N) ans = sum(ans, D);
	cout << ans << endl;
}