BEGIN { $/ = "\n"; $\ = "\n"; }
use strict;
use warnings;
my $uninitialized;
print do {
    $uninitialized
};
print do {
    ()
};
print do {
    do {
        ()
    }
};
print do {
    0
};
print '----------';
print scalar do {
    $uninitialized
};
print scalar do {
    ()
};
print scalar do {
    do {
        ()
    }
};
print scalar do {
    0
};