import std.algorithm, std.array, std.container, std.range;
import std.string, std.conv;
import std.math, std.bigint, std.bitmanip, std.random;
import std.stdio, std.typecons;

const auto repeat = 10 ^^ 6;

void main()
{
  auto n = readln.chomp.to!int;
  auto xi = readln.split.map!(to!int).array;

  auto yi = xi.sort().uniq.array;

  if (yi.length >= 2)
    writeln(iota(yi.length - 1).map!(i => yi[i + 1] - yi[i]).reduce!(min));
  else
    writeln(0);
}