# use strict;
# use warnings;

chomp(my $N=<>);
my $m = 0;
if ($N ne '1') {
    chomp(my $x=<>);
    my @Xs = sort({$a <=> $b} split(/ /, $x));
    $m = 'Inf';
    for ($i = 0; $i < $#Xs; $i++) {
        if ($Xs[$i] ne $Xs[$i + 1]) {
            my $d = $Xs[$i + 1] - $Xs[$i];
            $m = $d if $d < $m;
        }
    }
    $m = 0 if $m eq 'Inf';
}
print($m, "\n");