def main():
    N = int(input())
    X = list(map(int, input().split()))
    X.sort()
    y = []
    for i in range(N-1):
        y.append(X[i+1]-X[i])
    if y.count(0) > 0 and y.count(0) < len(y):
        for j in range(y.count(0)):
            y.pop(y.index(0))

    print(min(y))
            
    

if __name__ == '__main__':
    main()