use strict;
use warnings;

my $xy = [ [5,4,2,3,1,12], [2,9,2,3,4,5] ];

my @xy;
#push x's and corresponding y coor. in
#a slight different AoA;
for ( 0 .. $#{$xy->[0]} ){
  push @xy, [ $xy->[0][$_], $xy->[1][$_] ]; 
}

#sort it by y;
@xy = sort { $a->[1] <=> $b->[1] } @xy;

print "value of x with largest y = $xy[-1][0]\n";
print "largest y = $xy[-1][1]\n";
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