N = int(input())
L = sorted(list(set(map(int, input().split()))))
if len(L) == 1:
    d = 0
else:
    d = abs(L[1] - L[0])
    for n in range(len(L)):
        if abs(L[n] - L[n-1]) < d:
            d = abs(L[n] - L[n-1])
print(d)