import sys
input=lambda: sys.stdin.readline().rstrip()
n=int(input())
X=sorted([int(i) for i in input().split()])
ans=float("inf")
for i in range(n-1):
  d=X[i+1]-X[i]
  if d>0:
    ans=min(d,ans)
if ans==float("inf"):
  print(0)
else:
  print(ans)