import sys

N = int(input())
x = list(map(int, input().split()))
x = list(set(x))
x = sorted(x)
mini = 10**6
if len(x) == 0:
    print('0')
    sys.exit(0)
for i in range(1, len(x)):
    a = x[i]-x[i-1]
    if a < mini:
        mini = a
print(mini)