3let	1let	num
ALA	A	0
ARG	R	1
ASN	N	2
ASP	D	3
CYS	C	4
GLU	E	5
GLN	Q	6
GLY	G	7
HIS	H	8
ILE	I	9
LEU	L	10
LYS	K	11
MET	M	12
PHE	F	13
PRO	P	14
SER	S	15
THR	T	16
TRP	W	17
TYR	Y	18
VAL	V	19