def main():
    N = int(input())
    X = tuple(map(int, input().split()))

    x = sorted(X)
    l = [float('inf')] * (N - 1)
    for i in range(N - 1):
        dist = x[i+1] - x[i]
        if dist > 0:
            l[i] = dist

    print(min(l))

main()