Returns a substring of a specified length from the left of a string.
 LEFT$    ( string  , number of characters ] )
            └─┬──┘       └──────┬────────┘          
   String expression   Numeric expression  
LEFT$("ABCDEF", 3)
10  A$="ABCDEFGHIJKLMNOPQRSTUVWXYZ"
20  PRINT A$
30  INPUT "1 TO 26 HOW MANY GET"; N
40  PRINT LEFT$(A$, N)
50 END
Uses numeric input to display specified number of characters from beginning of alphabetic sequence.