N = int(input())
X = list(map(int,input().split()))
X.sort()
    
ans=10**5
for i in range(N-1):
    for j in range(i+1,N):
        if abs(X[i]-X[j])!=0:
            ans=min(ans,abs(X[i]-X[j]))

if ans==10**5:
    print(0)
else:
    print(ans)