#coding=UTF-8

N=int(input())

mojir=input()
#総当たりしたらO(N^2)
#隣り合うのにしたらO(N)

hyo=mojir.split(" ")
hyoon=list(range(0,N,1))
for idx in range(0,N,1):
    hyoon[idx]=int(hyo[idx])
#remove dup
hyon=list(set(hyoon))
myon=sorted(hyon)

#対称
dist=[]
for idx in range(0,len(myon)-1,1):
    dist.append(myon[idx+1]-myon[idx])

#print(dist)
if len(dist) != 0:
    print(min(dist))    
else:
    print(0)