N=int(input())
X=list(map(int,input().split()))
X.sort()
ans=[]
if sum(X)==0:
    print(0)
else:
    for i in range(N-1):
        dec=X[i+1]-X[i]
        if not dec==0:
            ans.append(dec)
    if ans!="":
        print(min(ans))
    else:
        print(0)