#!/usr/bin/perl
use warnings;
use strict;


open (FILE,"sequence.txt");


my $substring = 'GATC';
my$i=0;
my$count;
my $sequence;

while ($sequence=<FILE>){
	
    foreach($sequence =~ /$substring/) { 
   #print "malakas\n";
    	    
    	    #print "$count\n";
    }
    $count++; 
}
    print "There are $count negative numbers in the string";