import sys
from collections import defaultdict

def main():
    n = int(sys.stdin.readline())
    a = list(map(int, sys.stdin.readline().split()))

    count = defaultdict(int)
    for num in a:
        count[num] += 1

    # Precompute cnt for each element
    cnt = [0] * n
    for i in range(n):
        ai = a[i]
        current_cnt = 0
        for k in range(30):
            target = ai ^ (1 << k)
            current_cnt += count.get(target, 0)
        cnt[i] = current_cnt

    # Sort indices based on cnt, then value to break ties
    sorted_indices = sorted(range(n), key=lambda x: (cnt[x], a[x]))

    max_size = 0
    selected = []

    for idx in sorted_indices:
        current_num = a[idx]
        valid = True
        for s in selected:
            xor = current_num ^ s
            if xor & (xor - 1) == 0 and xor != 0:
                valid = False
                break
        if valid:
            selected.append(current_num)
            if len(selected) > max_size:
                max_size = len(selected)

    print(max_size)

if __name__ == "__main__":
    main()