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Select Code to Download

Select or download this
```
my $a = "17341234";
```
Select or download this
```
$a=~s/(.)(...)\1/A$2B/g;
print "$a\n";
```
Select or download this
```
A7AAB2BB
```
Select or download this
```
A734B234
```

Select or download this

$a=~s/(.)(?=...\1)/A/g;
$a=~s/(?<=A...)(.)/B/g;
print "$a\n";

Select or download this
```
A7AAB2BB
```