#include <iostream>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <tuple>
#include <cmath>
#include <numeric>
#include <functional>
#include <cassert>

#define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl;
#define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

using namespace std;
typedef long long ll;

template<typename T>
vector<vector<T>> vec2d(int n, int m, T v){
    return vector<vector<T>>(n, vector<T>(m, v));
}

template<typename T>
vector<vector<vector<T>>> vec3d(int n, int m, int k, T v){
    return vector<vector<vector<T>>>(n, vector<vector<T>>(m, vector<T>(k, v)));
}

template<typename T>
void print_vector(vector<T> v, char delimiter=' '){
    if(v.empty()) {
        cout << endl;
        return;
    }
    for(int i = 0; i+1 < v.size(); i++) cout << v[i] << delimiter;
    cout << v.back() << endl;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << setprecision(10) << fixed;
    int n; cin >> n;
    string s, t; cin >> s >> t;
    for(int i = 0; i < n; i++){
        int ss = (s[i]-'0') + (s[i+n]-'0');
        int tt = (t[i]-'0') + (t[i+n]-'0');
        if((ss == 0 && tt != 0) | (ss != 0 && tt == 0)){
            cout << -1 << endl;
            return 0;
        }
    }
    auto get_s = [&](int i){
        string ans;
        ans += s[i];
        ans += s[i+n];
        return ans;
    };
    auto get_t = [&](int i){
        string ans;
        ans += t[i];
        ans += t[i+n];
        return ans;
    };
    vector<int> ans;
    auto op = [&](int idx){
        for(int i = idx; i < idx+n; i++){
            int x = (s[i]-'0')^(s[(i+n)%(2*n)]-'0');
            s[i] = '0'+x;
        }
        ans.push_back(idx);
    };
    for(int i = 0; i < n; i++) {
        string ss = get_s(i);
        string tt = get_t(i);
        if(ss == tt) continue;
        if(ss == "01"){
            if(tt == "11"){
                op(n);
                op(i);
            }
            if(tt == "10"){
                op(i);
                op(n);
            }
        }
        if(ss == "10"){
            if(tt == "11"){
                op(i);
                op(n);
            }
            if(tt == "01"){
                op(n);
                op(i);
            }
        }
        if(ss == "11"){
            if(tt == "01"){
                op(n);
                op(i);
            }
            if(tt == "10"){
                op(i);
                op(n);
            }
        }
    }
    cout << ans.size() << endl;
    print_vector(ans);
}