N = int(input())
L = list(map(int,input().split()))
L = list(set(L))
L = sorted(L)
ans = float("inf")
if len(L) == 1 :
    ans = 0
else :
    for i in range(len(L)-1) :
        calc = L[i+1]-L[i]
        ans = min(ans,calc)
print(ans)