#include <iostream>
#include <string>
#include <vector>
#include <utility>

using namespace std;
pair<int,int> p[1010],q[1010];
void ope(int x,int j){
    if(x==0) p[j].first ^= p[j].second;
    else p[j].second ^= p[j].first;
}

vector<int> ans;
void solve(int x,int n){
    ans.push_back(x);
    if(x<=n){
        for(int i=0;i<n;i++) ope((i<x),i);
    }else{
        x -= n;
        for(int i=0;i<n;i++) ope((i>x - n),i);
    }
}

int a[1010],b[1010];
void ch(int x,int n){
    for(int i=0;i<n;i++){
        a[x + i] ^= a[(x + i + n)%(2*n)];
    }
}

int main(){
    int i,j,n; cin >> n;
    string s,t; cin >> s >> t;
    for(i=0;i<n;i++){
        p[i].first = s[i] - '0'; p[i].second = s[i + n] - '0';
        q[i].first = t[i] - '0'; q[i].second = t[i + n] - '0';
    }
    for(i=0;i<2*n;i++){
        a[i] = s[i] - '0'; b[i] = t[i] - '0';
    }
    /*for(i=0;i<n;i++) cout << p[i].first << p[i].second << endl;
    cout << endl;
    for(i=0;i<n;i++) cout << q[i].first << q[i].second << endl;*/
    for(i=0;i<n;i++){
        int x = p[i].first*2 + p[i].second,y = q[i].first*2 + q[i].second;
        if(x==0 && y!=0){
            cout << -1 << endl;
            return 0;
        }
        if(x!=0 && y==0){
            cout << -1 << endl;
            return 0;
        }
    }
    for(i=0;i<n;i++){
        int x = p[i].first*2 + p[i].second,y = q[i].first*2 + q[i].second;
        if(x==y) continue;
        //cout << i << " " << x << " " << y << endl;
        if((x&y)==0){
            if(x==1){//1-2
                solve(0,n); solve(n + i,n);
            }
            if(x==2){//2-1
                solve(n,n); solve(i,n);
            }
        }else{
            if(x==1){//1-3
                solve(n,n); solve(i,n);
            }
            if(x==2){//2-3
                solve(0,n); solve(n + i,n);
            }
            if(x==3){
                if(y==1){//3-1
                    solve(0,n); solve(n + i,n);
                }
                if(y==2){//3-2
                    solve(n,n); solve(i,n);
                }
            }
        }
    }
    cout << ans.size() << endl;
    for(i=0;i<ans.size();i++) cout << ans[i] << endl;
    for(i=0;i<n;i++){
       // cout << p[i].first << " " << p[i].second << " " << q[i].first << " "<< q[i].second << endl;
    }
    /*for(i=0;i<2*n;i++) cout << a[i];
    cout << endl;
    for(i=0;i<n;i++) cout << p[i].first;
    for(i=0;i<n;i++) cout << p[i].second;
    cout << endl;*/
    /*for(i=0;i<2*n;i++) cout << a[i];
    cout << endl;
    for(i=0;i<ans.size();i++){
        ch(ans[i],n);
        for(j=0;j<2*n;j++) cout << a[j];
        cout << endl;
    }
    for(i=0;i<2*n;i++) cout << a[i];
    cout << endl;*/
}