Table 1 - Converting Months to Letters

Convert the birth month into a character from the first column of letters, unless this would give a duplicate license number. In that case, use the character in the second column.

January	B	S	July	M	4
February	C	T	August	N	5
March	D	U	September	O	6
April	J	1	October	P	7
May	K	2	November	Q	8
June	L	3	December	R	9