#line 1 "main.cpp"
#include <iostream>
#include <vector>
#include <set>
#include <string>

using namespace std;

const set<pair<int, int>> ls{{1, 2}, {2, 3}, {3, 1}};

void solve() {
    int n;
    string s, t;
    cin >> n >> s >> t;

    vector<int> ans;
    auto ope = [&](int i, char c) {
        if (c == 'R') i += n;
        ans.push_back(i);

        for (int d = 0; d < n; ++d) {
            int j = (i + d) % (n * 2);
            int k = (j + n) % (n * 2);

            if (s[k] == '1') s[j] ^= 1;
        }
    };

    for (int i = 0; i < n; ++i) {
        int x = (s[i] - '0') * 2 + (s[i + n] - '0');
        int y = (t[i] - '0') * 2 + (t[i + n] - '0');
        if (x == y) continue;

        if (x == 0 || y == 0) {
            cout << "-1\n";
            return;
        }

        if (ls.count({x, y})) {
            ope(i, 'L');
            ope(0, 'R');
        } else {
            ope(i, 'R');
            ope(0, 'L');
        }
    }

    cout << ans.size() << "\n";
    for (auto i : ans) cout << i << "\n";
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    solve();

    return 0;
}