from math import sqrt, acos, pi, cos, log2, ceil, floor

n = int(input())

numbers = [int(x) for x in input().split()]

size = 74

def to_binary(x):
    res = [0 for _ in range(size)]
    k = floor(log2(x))

    if x == 0:
        return res

    for i in range(k, -1, -1):
        if x >= 2**i:
            res[i] = 1
            x -= 2**i
            
    #print(*res)
    return res 


dp = [to_binary(x) for x in numbers]

#the rest from previous
suma = 0
for i in range(size):
    for j in range(n):
        suma += dp[j][i]
    
    dp[-1][i] = suma
    #print(*dp)
    suma = int(suma/2)

#print(dp[-1])
res = 0
for i in range(size):
    if dp[-1][i]:
        res += 2**i

print(res)