#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define pb emplace_back
#define AI(i) begin(i), end(i)
template<class T> bool chmin(T &a, T b) { return b < a && (a = b, true); }
template<class T> bool chmax(T &a, T b) { return a < b && (a = b, true); }
#ifdef KEV
#define DE(args...) kout("[ " + string(#args) + " ] = ", args)
void kout() { cerr << endl; }
template<class T, class ...U> void kout(T a, U ...b) { cerr << a << ' ', kout(b...); }
template<class T> void debug(T l, T r) { while (l != r) cerr <<setw(2) << *l << " \n"[next(l)==r], ++l; }
#else
#define DE(...) 0
#define debug(...) 0
#endif
const int MAX_N = 17, inf = 1e9;
int n;
int a[(1<<MAX_N) + 10];
map<vector<int>, string> st;
int cntinv(vector<int> a) {
vector<int> cnt((1<<n)+1);
auto qry = [&](int i) {
++i;
int res = 0;
for (;i <= (1<<n);i += i&-i)
res += cnt[i];
return res;
};
auto add = [&](int i) {
++i;
for (;i;i ^= i&-i)
++cnt[i];
};
int res = 0;
for (int x : a) {
res += qry(x);
add(x);
}
return res;
}
// swap left right
vector<int> aop(vector<int> vec) {
vector<int> a;
int m = vec.size();
{
// A
for (int i = m/2;i < m;++i)
a.pb(vec[i]);
for (int i = 0;i < m/2;++i)
a.pb(vec[i]);
}
return a;
}
// odd and even
vector<int> bop(vector<int> vec) {
vector<int> b;
int m = vec.size();
{
// B
for (int i = 0;i < m;i += 2)
b.pb(vec[i]);
for (int i = 1;i < m;i += 2)
b.pb(vec[i]);
}
return b;
}
void dfs(vector<int> vec, int lev) {
static string ops;
if (st.count(vec)) return;
st[vec] = ops;
ops += '1';
dfs(aop(vec), lev);
++ops.back();
dfs(bop(vec), lev);
ops.pop_back();
}
int32_t main() {
ios_base::sync_with_stdio(0), cin.tie(0);
cin >> n;
if (n == 0) return cout << "0\n\n", 0;
vector<int> a(1<<n), tar(1<<n);
iota(AI(tar), 0);
for (int &i : a) cin >> i;
string res;
while (a[0]) {
vector<vector<int>> cand;
{
auto now = a;
for (int i = 0;i < n;++i) {
cand.pb(now);
now = bop(now);
}
}
int mnv = inf, pos = -1;
for (int i = 0;i < n;++i) {
if (chmin(mnv, cand[i][(1<<(n-1))]))
pos = i;
}
res += string(pos, '2');
a = cand[pos];
res += '1';
a = aop(a);
}
while (a != tar) {
res += '2';
a = bop(a);
}
cout << 0 << '\n' << res << '\n';
}
