import strutils, sequtils, algorithm, math

var
  n = readLine(stdin).parseInt
  x_seq = split(readLine(stdin), ' ').map(parseInt)
  min_v = high(int)

x_seq = x_seq.deduplicate()
x_seq.sort(cmp[int])

for i in countup(0, n - 2):
  min_v = min(min_v, abs(x_seq[i] - x_seq[i + 1]))

echo(min_v)