import strutils, sequtils, math

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

for i in countup(0, n - 2):
  for j in countup(1, n - 1):
    tmp = abs(x_seq[i] - x_seq[j])
    if tmp > 0 and min_v > tmp:
      min_v = tmp

echo(min_v)