//
// Created by BigBag on 22.07.2023 10:55:33
//

#include <bits/stdc++.h>

#define F first
#define S second
#define MP make_pair
#define PB push_back

#define all(a) a.begin(), a.end()
#define len(a) (int) (a.size())
#define mp make_pair
#define pb push_back
#define fir first
#define sec second

using namespace std;

typedef pair<int, int> pii;
typedef long long ll;
typedef long double ld;

#ifdef Energy_is_not_over
#define DEBUG for (bool ____DEBUG = true; ____DEBUG; ____DEBUG = false)
#define LOG(...) print(#__VA_ARGS__" ::", __VA_ARGS__) << endl

template<class ...Ts>
auto &print(Ts ...ts) { return ((cerr << ts << " "), ...); }

#else
#define DEBUG while (false)
#define LOG(...)
#endif

const int max_n = 1000111, inf = 1000111222;

int tests, n, a[max_n];
string s, t;

int main() {
//    freopen("input.txt", "r", stdin);
//    freopen("output.txt", "w", stdout);
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    cin >> tests;
    while (tests--) {
        cin >> n >> s >> t;
        for (int i = 0; i < n; ++i) {
            a[i] = s[i] ^ t[i];
        }
        for (int i = n - 1; i; --i) {
            a[i] ^= a[i - 1];
        }
        long long ans = 0;
        int ones = accumulate(a, a + n, 0);
        int ones_to_right = ones;
        for (int i = 0; i < n; ++i) {
            ones_to_right -= a[i];
            ones -= a[i];
            ones += 1 - a[i];
            LOG(i, ones, a[i]);
            ans += (ones == 1 || ones == 2);
            vector<int> ways{n - 1 - i - ones_to_right, ones_to_right};
            for (int other = 0; other < 2; ++other) {
                if (!ways[other]) {
                    continue;
                }
                ones -= other;
                ones += 1 - other;
                if (ones == 1 || ones == 2) {
                    LOG(i, other, ones, ways[other], ans);
                    ans += ways[other];
                }
                ones -= 1 - other;
                ones += other;
            }
            ones -= 1 - a[i];
            ones += a[i];
        }
        cout << ans << "\n";
    }
    return 0;
}