Module Expr Str Assign NameStore SubscriptLoad Str Index Num Print NameLoad
N/A N/A 
The string "PYTHON" has six characters,
numbered 0 to 5, as shown below:

+---+---+---+---+---+---+
| P | Y | T | H | O | N |
+---+---+---+---+---+---+
  0   1   2   3   4   5

So if you wanted "Y", you could just type
"PYTHON"[1] (always start counting from 0!)
 N/A fifth_letter N/A MONTY N/A 4 N/A fifth_letter