_ = int(input())
X = set(map(int, input().split()))
X = list(sorted(X))
ans = 10**6 + 1
N = len(X)
if N == 1:
    exit(print(0))
for i in range(N - 1):
    pos, nex = X[i], X[i + 1]
    diff = nex - pos
    ans = min(ans, diff)
print(ans)