#include <bits/stdc++.h>
using std::cin, std::cout;

void D() { std::cerr << "\n"; }
template <typename T, typename...Args>
void D(T t, Args...args) { std::cerr << t << ' '; D(args...); }

using ull = unsigned long long;

inline ull reverse_ull(ull x)
{
    ull res = 0;
    for (int block = 0; block < 8; block++)
    {
        res <<= 8;
        res |= x & 0b11111111;
        x >>= 8;
    }
    return res;
}

void encode()
{
    int n;
    cin >> n;

    std::vector<ull> data(n + 5);
    for (int i = 1; i <= n; i++) cin >> data[i];

    std::vector<ull> chksum(n + 5);
    for (int i = 1; i <= n; i++)
    {
        ull t1 = data[i], t2 = reverse_ull(data[i]);
        if (t1 > t2) chksum[i] = 1;
        else chksum[i] = 0;
    }

    std::vector<ull> payload;
    int idx = 1;
    while (idx <= n)
    {
        ull d = 0x8000'0000'0000'0000;
        for (int j = 0; idx <= n && j < 64; j++)
        {
            if (j == 7 || j == 63) continue;
            d |= chksum[idx++] << j;
        }
        payload.push_back(d);
    }
    payload.resize(20);

    for (int i = 1; i <= n; i++) payload.push_back(data[i]);

    cout << payload.size() << "\n";
    for (auto it : payload) cout << it << " ";
}

void decode()
{
    int len;
    cin >> len;

    std::vector<ull> payload(len);
    for (auto &it : payload) cin >> it;

    std::vector<ull> chksum;
    for (int i = 0; i < 20; i++)
    {
        if ((payload[i] >> 7) & 1) payload[i] = reverse_ull(payload[i]);

        for (int j = 0; j < 64; j++)
        {
            if (j == 7 || j == 63) continue;
            chksum.push_back((payload[i] >> j) & 1);
        }
    }

    std::vector<ull> data;
    for (int i = 20; i < payload.size(); i++) data.push_back(payload[i]);

    for (int i = 0; i < data.size(); i++)
    {
        ull t1 = data[i], t2 = reverse_ull(data[i]);
        if (chksum[i] == 1)
            data[i] = std::max(t1, t2);
        else
            data[i] = std::min(t1, t2);
    }

    for (auto it : data) cout << it << " ";
}

int main()
{
    std::string str;
    cin >> str;
    if (str == "encode") encode();
    else decode();
}