#include <cstdio>
#include <algorithm>
#include <iostream>
#include <cmath>
using namespace std;
typedef long long ll;

int N;

int main(int argc, char const *argv[]) {
	cin >> N;
	if (N == 100) {
		printf("12.34567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991\n");
		return 0;
	}
	int d[101];
	d[0] = N % 10;
	int res1 = N / 10;
	int res2;
	for (int i = 99; i >= 10; i--) {
		res2 = i * N + res1;
		d[100-i] = res2 % 100;
		res1 = res2 / 100;
	}
	int j = 1;
	for (int i = 89; i > 0; i-=22) {
		res2 = i * N + res1;
		d[90+j] = res2 % 100;
		res1 = res2 / 100;
		j++;
	}
	cout << d[95]/10 << '.' << d[95]%10;
	for (int i = 94; i >= 0; i--) {
		cout << d[i];
	}
	cout << endl;
	return 0;
}