import std.stdio, std.algorithm;
void main() {
	double i;
	while ("%f\n".readf(&i)) {
		double[] a = [i];
		foreach (j; 2..11) {
			if (j % 2 == 0)
				a ~= a[$-1] * 2.0;
			else
				a ~= a[$-1] / 3.0;
		}
		"%.8f".writefln(a.reduce!"a+b");
	}
}