// TODO problem 24
public long Solve()
{
long seachItem = 1000000;
var digits = Enumerable.Range(0, 10).ToList();
var str = "";
for (int i = 9; i > 0; i--)
{
var fac = ExtraMath.Factorial(i);
var index = (int)(seachItem / fac);
str += digits.ElementAt(i);
digits.RemoveAt(index);
seachItem %= fac;
}
str += digits.Last();
return(long.Parse(str));
}
