N = int(input())
X = list(map(int, input().split()))
ans = 10**9
X.sort()
now = X[0]
flag = False
for i in range(1, N):
    if now == X[i]:
        now = X[i]
        continue
    ans = min(ans, abs(X[i]-now))
    now = X[i]
    flag = True
if flag:
    print(ans)
else:
    print(0)