#include <bits/stdc++.h>
using namespace std;


#ifdef WINVER
#define QAQ "%I64d"
#else
#define QAQ "%lld"
#endif

typedef long long int i64;

i64 d[64], P[64];
int main()
{
    freopen("asm_contribute.in", "r", stdin);
#ifndef debug
    freopen("asm_contribute.out", "w", stdout);
#endif
    int n; scanf("%d", &n);
    i64 ans = 0;
    
    for (int i = 0; i < n; ++i)
    {
        i64 x, hh = (1 << i); scanf(QAQ, &x);
        for (int j = 63; j >= 0; --j) if (x >> j & 1)
        {
            if (d[j])
            {
                x ^= d[j]; hh ^= P[j];
                if (!x)
                {
                    ans = hh;
                    goto fail;
                }
            } else
            {
                d[j] = x; P[j] = hh;
                break;
            }
        }
    } fail:
    printf("%d\n", __builtin_popcountll(ans));
    for (int i = 0; i < 63; ++i)
        if (ans >> i & 1) printf("%d%c",  i + 1, " \n"[!(ans >> (i + 1))]);
}