N = int(input())
X = sorted(map(int, input().split()))

ans = None
for i in range(N-1):
    if X[i] != X[i+1]:
        if ans is None:
            ans = X[i+1] - X[i]
        else:
            ans = min(ans, X[i+1] - X[i])
if ans is None:
    ans = 0
print(ans)