N=int(input())
X=list(set(map(int,input().split())))
if len(X)<=1: print(0)
else:
  X.sort()
  m=X[1]-X[0]
  for e in range(1,len(X)-1):
    t=X[e+1]-X[e]
    if m>t: m=t
  print(m)