#! perl -slw
use strict;

while( 1 ) {
	my @t1 = map{ "T1/$_" } 1 .. 7;
	my @t2 = map{ "T2/$_" } 1 .. 7;
	my @seq = map{ 
		shift @{ 
            ( ( rand() < .5 ) and @t1 ) 
             ? \@t1 
             : \@t2 
        } 
	} 1 .. @t1 + @t2;
	print @seq . " :@seq"; <STDIN>;
}
__END__
P:\test>junk.pl
14 :T2/1 T2/2 T1/1 T1/2 T1/3 T2/3 T2/4 T1/4 T2/5 T2/6 T1/5 T2/7 T1/6 T1/7

Use of uninitialized value in join or string at P:\test\junk.pl line 10, <STDIN> line 1.
14 :T2/1 T1/1 T1/2 T1/3 T1/4 T2/2 T2/3 T2/4 T1/5 T2/5 T1/6 T2/6 T2/7

14 :T1/1 T1/2 T1/3 T1/4 T1/5 T1/6 T2/1 T2/2 T1/7 T2/3 T2/4 T2/5 T2/6 T2/7

14 :T1/1 T1/2 T1/3 T1/4 T2/1 T1/5 T1/6 T1/7 T2/2 T2/3 T2/4 T2/5 T2/6 T2/7

Use of uninitialized value in join or string at P:\test\junk.pl line 10, <STDIN> line 4.
14 :T1/1 T2/1 T1/2 T1/3 T2/2 T2/3 T1/4 T2/4 T2/5 T2/6 T1/5 T1/6 T2/7
Terminating on signal SIGINT(2)