string autoincrement

print ++($a = "ay");
print "\n\n";

print ++($a = "QZ");
print "\n\n";

print ++($a = "Qz");
print "\n\n";

print ++($a = "b1");
print "\n\n";

print ++($a = "zz");




__END__
OUTPUT:

az

RA

Ra

b2

aaa