$\ = $/;

sub add{
    my ($i, $j, $add) = @_;
    $_{value}[$i][$j] += $add;
    }

while(<DATA>){
    
    $tc ++;
    print "[$tc]";
    
    ($n, $m) = split;
    for $i (1 .. $n){
        $_ = <DATA>, chomp;
        for $j (1 .. $m){
            $_{value}[$i][$j] = substr $_, $j - 1, 1;
        }
    }

    &add(2, 3, 5);

    for $i (1 .. $n){
        print join " ", @{ $_{value}[$i] };
    }
}
__DATA__
3 3
011
111
111
6 7
1101011
0111111
1111101
1111111
1111110
0111111
[download]

OUTPUT:

[1]
 0 1 1
 1 1 6
 1 1 1
[2]
 1 1 0 1 0 1 1
 0 1 6 1 1 1 1
 1 1 1 1 1 0 1
 1 1 1 1 1 1 1
 1 1 1 1 1 1 0
 0 1 1 1 1 1 1
[download]

... but later I wanted to collect all my matrixes, so I tried to replace this "$_{value}[$i]" with that "$_[$tc]{value}[$i]" (I inserted [$tc] in all such places). And now seems that my subroutine fails? The OUTPUT is:

[1]
 0 1 1
 1 1 1
 1 1 1
[2]
 1 1 0 1 0 1 1
 0 1 1 1 1 1 1
 1 1 1 1 1 0 1
 1 1 1 1 1 1 1
 1 1 1 1 1 1 0
 0 1 1 1 1 1 1
[download]

Program:

$\ = $/;

sub add{
    my ($i, $j, $add) = @_;
    $_[$tc]{value}[$i][$j] += $add;
    }

while(<DATA>){
    
    $tc ++;
    print "[$tc]";
    
    ($n, $m) = split;
    for $i (1 .. $n){
        $_ = <DATA>, chomp;
        for $j (1 .. $m){
            $_[$tc]{value}[$i][$j] = substr $_, $j - 1, 1;
        }
    }

    &add(2, 3, 5);

    for $i (1 .. $n){
        print join " ", @{ $_[$tc]{value}[$i] };
    }
}
__DATA__
3 3
011
111
111
6 7
1101011
0111111
1111101
1111111
1111110
0111111
[download]

I can't understand why it fails.