#!perl
use strict;

my $str  = '0000000NNNN00NNN0NNN0N0N0NN0N';
my @str = split '',$str;

# input 
my @mask = map{ 'N' }(0..$#str);
while (<DATA>){
  chomp;
  my (undef,$start,$end) = split "[,\t]",$_;
  for my $ix ($start..$end){
    $mask[$ix-1] = ' ';
  }
}

# process
my @output=();
for my $ix (0..$#str){
  $output[$ix] = ($mask[$ix] eq 'N') ? 'N' : $str[$ix];
}

# output
print 'mask   ',join '',@mask,"\n";
print 'string ',join '',@str,"\n";
print 'result ',join '',@output,"\n";

# intervals no,start,end
__DATA__
1,2,4
2,6,10
3,20,25
4,28,28