• Try to split a string, not an array
• Your source data is only partly separated with "-"

my $account = "34765-22333-333489-99867-22340-23456-3229-XLM8876-AMP77
+65-WQP22349";
my @chk_acc = split("-",$account);
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HTH, Rata (wondering about the useless chomp() ... not the first time today ...)