INF = 1<<32
N = int(input())
X = list(map(int,input().split()))
X.sort()
ans = INF
for i in range(N-1):
    if X[i] == X[i+1]:
        continue
    ans = min(ans, X[i+1]-X[i])
if ans == INF:
    ans = 0
print(ans)