n = int(input())
l = [int(i) for i in input().split()]

min = 10000000

for i in range(len(l)-1):
    for j in range(i+1,len(l)):
        if abs(l[i]-l[j]) < min and l[i] != l[j]:
            min = abs(l[i]-l[j])

print(min)