import math
n = int(input())
l = list(map(int, input().split()))
min = 0
if n <= 1 or len(set(l)) == 0:
    print('0')
else:
    for i in range(n):
        for j in range(n):
            if not l[i] == l[j]:
                if min == 0 or abs(l[i] - l[j]) < min:
                    min = abs(l[i] - l[j])
    print(min)