N = int(input())
X = sorted([int(i) for i in input().split()])
min = 99999999
for i in range(N-1):
    if X[i] != X[i+1]:      
        if X[i+1]-X[i] < min:
            min = X[i+1]-X[i]
if min == 99999999:
    min = 0
print(min)