without code, it's a bit of a monsterformula but there are 2 ways of writing it. Either create a table as follows
0
48
58
65
91
97
123
name it myRange and use
=IF(AND(VLOOKUP(CODE(LEFT($E$1,1)),myRange,2,TRUE)="A",VLOOKUP(CODE(MID($E$1,2,1)),myRange,2,TRUE)="A",VLOOKUP(CODE(MID($E$1,3,1)),myRange,2,TRUE)="A",VLOOKUP(CODE(MID($E$1,4,1)),myRange,2,TRUE)="N",VLOOKUP(CODE(MID($E$1,5,1)),myRange,2,TRUE)="N",VLOOKUP(CODE(RIGHT($E$1,1)),myRange,2,TRUE)="N"),1,2
OR, without a table
=IF(AND(VLOOKUP(CODE(LEFT($E$1,1)),{0,"E";48,"N";58,"E";65,"A";91,"E";97,"A";123,"E"},2,TRUE)="A",VLOOKUP(CODE(MID($E$1,2,1)),{0,"E";48,"N";58,"E";65,"A";91,"E";97,"A";123,"E"},2,TRUE)="A",VLOOKUP(CODE(MID($E$1,3,1)),{0,"E";48,"N";58,"E";65,"A";91,"E";97,"A";123,"E"},2,TRUE)="A",VLOOKUP(CODE(MID($E$1,4,1)),{0,"E";48,"N";58,"E";65,"A";91,"E";97,"A";123,"E"},2,TRUE)="N",VLOOKUP(CODE(MID($E$1,5,1)),{0,"E";48,"N";58,"E";65,"A";91,"E";97,"A";123,"E"},2,TRUE)="N",VLOOKUP(CODE(RIGHT($E$1,1)),{0,"E";48,"N";58,"E";65,"A";91,"E";97,"A";123,"E"},2,TRUE)="N"),1,2)