n = int(input())
x = list(map(int, input().split()))

x = list(set(sorted(x)))

ans = float("inf")

for i in range(len(x)-1):
    if abs(x[i]-x[i+1]) <= ans and abs(x[i]-x[i+1]) != 0:
        ans = abs(x[i]-x[i+1])

print(ans)