#include <cstring>
#include <iostream>

constexpr size_t MAX_N = 201;
int n, evaluation_value, original_evaluation_value;
bool bits[MAX_N], original_bits[MAX_N], target_bits[MAX_N];

std::ostream& print_bits(const bool* bits_list = bits, std::ostream& os = std::clog) {
    for (int i = 0; i < n; i++) {
        os << (bits_list[i] ? 1 : 0);
    }
    return os;
}

void swap_bits(int i, int j) {
    if (bits[i] != target_bits[i]) { evaluation_value--; }
    if (bits[j] != target_bits[j]) { evaluation_value--; }
    std::swap(bits[i], bits[j]);
    if (bits[i] != target_bits[i]) { evaluation_value++; }
    if (bits[j] != target_bits[j]) { evaluation_value++; }
}

int evaluate() {
    if (evaluation_value == 1) { return 1; }
    return evaluation_value / 2;
}

bool dfs(int last_swap_pos = 0, int depth = 0, int target_depth = 0) {
    const int h = evaluate();
    if (h == 0) { return true; }
    if (depth + h > target_depth) {
        return false;
    }
    std::clog << "DEPTH=" << depth << "\th=" << h << "\t";
    print_bits() << "\t";
    print_bits(target_bits) << std::endl;
    for (int i = 0; i < n - 1; i++) {
        if (bits[i] == bits[i + 1]) { continue; }
        if (i == last_swap_pos) { continue; }
        if (bits[i] == target_bits[i] && bits[i + 1] == target_bits[i + 1]) { continue; }
        if ((bits[i] == target_bits[i] || bits[i + 1] == target_bits[i + 1]) &&
            (bits[i + 1] != target_bits[i] && bits[i] != target_bits[i + 1])) { continue; }
        swap_bits(bits[i], bits[i + 1]);
        if (dfs(i, depth + 1, target_depth)) { return true; }
        swap_bits(bits[i], bits[i + 1]);
    }
    return false;
}

int ida_star() {
    for (int target_depth = evaluate(); target_depth <= 2 * n; target_depth++) {
        memcpy(bits, original_bits, n);
        evaluation_value = original_evaluation_value;
        std::clog << "target_depth:" << target_depth << std::endl;
        if (dfs(-1, 0, target_depth)) {
            return target_depth;
        }
    }
    return -1;
}

bool init_evaluate() {
    int original_sum = 0, target_sum = 0;
    for (int i = 0; i < n; i++) {
        original_sum += original_bits[i];
        target_sum += target_bits[i];
        original_evaluation_value += original_bits[i] != target_bits[i];
    }
    return original_sum == target_sum;
}

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

    std::cin >> n;
    for (int i = 0; i < n; i++) { std::cin >> original_bits[i]; }
    for (int i = 0; i < n; i++) { std::cin >> target_bits[i]; }
    if (!init_evaluate()) {
        std::cout << -1 << std::endl;
        return 0;
    }
    std::cout << ida_star() << std::endl;

    return 0;
}