Permutations. Permutations. Permutations. Why should they be so difficult?
Martin O'Neill and the Republic of Ireland side are still no clearer about what their future in World Cup qualification after Saturday night's games.
A win against Wales in Cardiff is a must on Monday night, but there is still a possibility that it may not be enough to reach the play-offs. The eight best second-placed teams will reach the next stage, with one second-placed team missing out. Serbia, Wales and the Republic of Ireland are in danger of being that team.
Saturday started so well with Belgium defeated Bosnia and Herzegovina 4-3 in a thriller in Sarajevo. That meant that if Greece dropped points to Cyprus in Nicosia, then Ireland's fate would be in its own hands.
It all started so well with Cyprus taking the lead, but two goals in two first-half minutes from the Greeks helped them win 2-1. Alexandros Tziolis scored the decisive goal.
The Greek win means that all Irish eyes will be focused on two games in the coming days. On Sunday evening, if Scotland fail to beat Slovenia in Ljubljana, a win will be good enough for Ireland in Cardiff.
Should Scotland win, the focus will turn to Kiev on Monday evening where Ireland need Ukraine and Croatia to draw. A win for either side cannot happen for Ireland's hopes.
Lets get those Slovenia flags and scarves ready to wave!