n=int(input())
a=list(map(int,input().split()))
c=[[0,0] for i in range(31)]

for i in a:
    t=bin(i)[2:][::-1]
    for j in range(len(t)):
        c[j][int(t[j])] += 1

ans =''
for i,j in c:
    if i == 0 and j == 0:
        break
    if i > j:
        ans+='0'
    else:
        ans+='1'
        
ans=int(ans[::-1],2)

A=0
for i in a:
    A=max(i^ans,A)
print(A)