#include <bits/stdc++.h>
//#include <chrono>
//#pragma GCC optimize("Ofast")
using namespace std;
#define reps(i,s,n) for(int i = s; i < n; i++)
#define rep(i,n) reps(i,0,n)
#define Rreps(i,n,e) for(int i = n - 1; i >= e; --i)
#define Rrep(i,n) Rreps(i,n,0)
#define ALL(a) a.begin(), a.end()

using ll = long long;
using vec = vector<ll>;
using mat = vector<vec>;

ll N,M,H,W,Q,K,A,B;
string S;
using P = pair<ll, ll>;
const ll INF = (1LL<<60);

template<class T> bool chmin(T &a, const T b){
    if(a > b) {a = b; return true;}
    else return false;
}
template<class T> bool chmax(T &a, const T b){
    if(a < b) {a = b; return true;}
    else return false;
}
template<class T> void my_printv(std::vector<T> v,bool endline = true){
    if(!v.empty()){
        for(std::size_t i{}; i<v.size()-1; ++i) std::cout<<v[i]<<" ";
        std::cout<<v.back();
    }
    if(endline) std::cout<<std::endl;
}

void input(vec &v, int p){
    rep(i, N){
        char c; cin>>c;
        v[i] += (c == '1' ? p : 0);
    }
}

void output(vec &v){
    rep(i, N) cout<<((v[i]>>1)&1);
    cout<<endl;
    rep(i, N) cout<<(v[i]&1);
    cout<<endl<<endl;
}

vec ans;
void sousa(int pos, bool rev, vec &a){
    if(!rev) {
        ans.push_back(0);
        rep(i, N) a[i] ^= (a[i]&1)<<1;
    }
    else {
        ans.push_back(N + pos);
        rep(i, pos) a[i] ^= (a[i]&1)<<1;
        reps(i, pos, N) a[i] ^= (a[i]>>1)&1;
    }
    //output(a);
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cin>>N;
    vec a(N), b(N);
    input(a, 2); input(a, 1);
    input(b, 2); input(b, 1);
    //output(a);
    rep(i, N){
        if(a[i] * b[i] == 0 && a[i] + b[i] != 0){
            cout<<-1<<endl;
            return 0;
        }
    }
    int id = -1;
    rep(i, N){
        if(a[i] == 0) continue;
        if(b[i] == 2){
            if(a[i] == 1) sousa(0, false, a);
            if(a[i] == 3) sousa(0, false, a);
        }else if(id == -1){
            id = i;
            if(a[i] == 2) sousa(i, true, a);
        }else{
            if(a[i] == 2){
                if((b[i] == 3) ^ (a[id] != b[id])) sousa(0, false, a);
                sousa(i, true, a);
            }else{
                if(a[i] == 3) sousa(0, false, a);
                //if(i == 2) cout<<(b[i] == a[i])<<' '<<id_same<<endl;
                if((b[i] == a[i]) ^ (a[id] == b[id])) sousa(i, true, a);
            }
        }
    }
    if(a != b) sousa(0, false, a);
    assert(a == b);
    cout<<ans.size()<<endl;
    for(ll r : ans) cout<<r<<endl;
}