# use strict;
# use warnings;

chomp(my $N=<>);
my $m = 0;
if ($N != 1) {
    chomp(my $x=<>);
    my @Xs = sort({$a <=> $b} split(/ /, $x));
    $m = 'Inf';
    my $p = shift(@Xs);
    foreach (@Xs) {
        my $d = $_ - $p;
        $m = $d if ($d && $d < $m);
        $p = $_;
    }
    $m = 0 if $m == 'Inf';
}
print($m, "\n");