n = int(input())
num = [ int(v) for v in input().split() ]
num.sort()
num2 = [ num[i+1] - num[i] for i in range(n - 1) if num[i+1] != num[i]  ]
    

if len(num2) > 0:
    print(min(num2))
else:
    print(0)