$a = 1;
$b = 0;

print "OR\n" if $a or $b;
print "AND\n" if $a and $b;

if ($a) {
    if ($b) {
        print "AND\n";
    } else {
        print "OR\n";
    }
} elsif ($b) {
    if ($a) {
        print "AND\n";
    } else {
        print "OR\n";
    }
}