Let's say we have a hypothetical complete schedule of potential outcomes from an experiment.

```
Y0<-c(10,15,20,20,10,15,15)
Y1<-c(15,15,30,15,20,15,30)
budgets<-matrix(data=c(Y0,Y1),nrow=7,ncol=2)

```

I would like to list all of the ways to choose two elements from Y1 and the remaining 5 from Y0. Ideally, this would look like an array of 21 lists, each with two elements labeled Y0 and two elements labeled Y1.

**edit:** These are matched pairs, so choosing `y0[1]` removes `y1[1]` from consideration.

Thanks in advance! I think there are many ways to approach this (sapply?) but would appreciate help on the details.