my %corr;
while (<>) {
my ($sx, $sy, $cx, $cy) = /(-?\d+)/g;
my $r = abs($sx - $cx) + abs($sy - $cy);
my $dist = abs($sy - $row);
my %corr;
while (<>) {
my ($sx, $sy, $cx, $cy) = /(-?\d+)/g;
my $r = abs($sx - $cx) + abs($sy - $cy);
my $dist = abs($sy - $row);