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

min_d = float("INF")
for i in range(N-1):
    if X[i] != X[i+1]:
        min_d = min(min_d, X[i+1]-X[i])
if min_d != float("INF"):
    print(min_d)
else:
    print(0)