def load():
    return list(map(int, input().split()))

def combinations(iterable, r):
    # combinations('ABCD', 2) --> AB AC AD BC BD CD
    # combinations(range(4), 3) --> 012 013 023 123
    pool = tuple(iterable)
    n = len(pool)
    if r > n:
        return
    indices = list(range(r))
    yield tuple(pool[i] for i in indices)
    while True:
        for i in reversed(range(r)):
            if indices[i] != i + n - r:
                break
        else:
            return
        indices[i] += 1
        for j in range(i+1, r):
            indices[j] = indices[j-1] + 1
        yield tuple(pool[i] for i in indices)

def solve():
    d = 0
    n = int(input())
    numbers = load()
    possibleSubsetSums = set()
    for i in range(n + 1):
        for subset in list(combinations(numbers, i)):
            possibleSubsetSums.add(sum(subset))
    for a in possibleSubsetSums:
        d = d | a
    print(d)

def main():
    # t = int(input())
    t = 1
    for i in range(t):
        solve()
if __name__ == "__main__":
    main()