When we toss a coin, there is possibility either head will come or tail will come.
If head comes, then dice will be rolled. Then, there can be 6 out comes.
In that case, possible outcomes `H1,H2,H3,H4,H5,H6`.
If, tail will come, nothing will be done. So, here is only a single outcome.
In that case, only possible outcome is `T`.
So, sample space will be `= 6+1 = 7`