import sys

N = int(input())
X = list(map(int, input().split()))
X.sort(reverse=True)

_min = sys.maxsize
for i in range(N - 1):
    if (X[i] - X[i + 1]) < _min and (X[i] != X[i + 1]):
        _min = X[i] - X[i + 1]

print(_min if _min != sys.maxsize else 0)