N = int(input())
X = list(map(int,input().split()))
X = list(set(X))
X = sorted(X)
candidate = []
if len(X) == 1 :
    print(0)
else :
    for i in range(len(X)-1) :
        a = X[i+1] - X[i]
        candidate.append(a)
if len(candidate) >= 1 :
    print(min(candidate))