N = input()
x = map(int,raw_input().split())
D = list(set(x))
D.sort(reverse=True)
A=[]
if len(D) == 1:
    print abs(D[0])
else:
    for i in range(0,len(D)-1):
        A.append(abs(D[i]-D[i+1]))
    print min(A)