#include"bits/stdc++.h"
using namespace std;
typedef long long int ll;
typedef vector<ll> vi;
typedef pair<ll,ll> ii;
typedef vector<ii> vii;
typedef vector<vi> vvi;
typedef vector<vii> vvii;
#define IO_SPEED_UP ios::sync_with_stdio(false);cin.tie(NULL)
#define pb push_back
#define popb pop_back
#define popcount(x)  __builtin_popcountll(x)
const ll INF=1e18;
const ll mxn=1e5+1;
const string fuck="fuck";

bool fun(vi arr, ll n)
{
    ll sum = 0;
    ll i, j;

    for (i = 0; i < n; i++)
        sum += arr[i];

    if (sum % 2 != 0)
        return false;

    bool part[sum / 2 + 1];

    for (i = 0; i <= sum / 2; i++)
    {
        part[i] = 0;
    }

    for (i = 0; i < n; i++)
    {

        for (j = sum / 2; j >= arr[i];
             j--)
        {
            if (part[j - arr[i]] == 1 || j == arr[i])
                part[j] = 1;
        }
    }

    return part[sum / 2];
}

void solve()
{
    ll n, i;
    cin >> n;
    vi v(n);
    for(auto &x:v)cin>>x;

    if (!fun(v, n))
    {
        cout << 0 << endl;
        return;
    }
   for(ll i=0;i<n;i++)
    {
        if(v[i]%2)
        {
            cout<<1<<endl;
            cout<<i+1<<endl;
            return;
        }
    }
    ll temp = v[0];
    v.erase(v.begin());
    ll count=1;
    while(fun(v,n-1))
    {
        v.pb(temp);
        temp = v[0];
        v.erase(v.begin());
        count++;
    }

    cout<<1<<endl;
    cout<<count<<endl;


    

}

int main(void)
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    // ll t;
    // cin >> t;
    // while (t--)
        solve();

    return 0;
}