.
When you solve such problems and become familiar with them for the first time,
it is important and valuable to get from somebody a compact description of the full space of events.
In this problem, the full space of events is the space (the set) of all pairs (L,i),
where letter L is one of two symbols H or T and "i" is one of 6 integer numbers 1, 2, 3, 4, 5, 6.
"L" and "i" take their values INDEPENDENTLY: "L" takes two values, while "i" takes 6 values,
so the entire space of events consists of 2*6 = 12 pairs / (elements).