func main()
	var N: int :: cui@input().toInt(&)
	var ss: [][]char :: cui@input().split(" ")
	var a: []int :: #[N]int
	for i(0, N - 1)
		do a[i] :: ss[i].toInt(&)
	end for
	do a.sort()

	var ans: int :: 0
	for i(1, N - 1)
		var v: int :: a[i] - a[i - 1]
		if(v <> 0)
			if(ans = 0)
				do ans :: v
			else
				do ans :: [ans, v].min()
			end if
		end if
	end for
	do cui@print("\{ans}\n")
end func