use v6;

sub lazy_merge (@list is rw) returns Sub {
    my $last = 0;

    my $by_n = sub ($n) { my $k = 0; return -> $x { $x ?? $k += $n :: $k } };
    @list = @list.map:{ $by_n( $_ ) };

    return sub {
        my $low;
        for ( @list ) -> $sub {
            my $val = $sub();
            $val = $sub(<next>) if $val <= $last;
            $low = $val if !$low.defined || $val < $low;
        }
        return $last = $low;
    };
}

my $end   = @*ARGS[0] // 22;
my @prime = (2, 3, 5);
my $next  = lazy_merge( @prime );
for 1..$end { say $next() };