Stratified random assignment [duplicate]

This question already has an answer here:

• Stratified random sampling from data frame 3 answers

I need to use stratified random assignment of 8 subjects to control and treatment groups based on their body condition score (BCS) which can be high or low.

1. high
2. high
3. high
4. high
5. low
6. low
7. low
8. low

I need to randomly get 2 groups with equal number of high and low BCS in each group.