N = int(raw_input())
X = map(int, raw_input().split())
X.sort()
newX = [X[0]]
for i in range(1, N):
	if newX[-1] != X[i]: newX.append(X[i])
min = 1000001
for i in range(0, len(newX)):
	d = newX[i+1]-newX[i]
	if d < min: min = d
if len(newX) == 1: min = 0
print min