#include <bits/stdc++.h>
#define endl '\n'
#define int long long
using namespace std;

void solve() {
    int n;
    string s, t;
    cin >> n >> s >> t;
    s = ' ' + s;
    t = ' ' + t;
    vector<int> v(n + 1);
    int cnt = 0;
    for (int i = 1; i <= n; i++) {
        if ( s[i] != t[i] ) v[i] = 1;
        if ( v[i] != v[i - 1] && v[i] == 1 ) cnt++;
    }
    // cout << cnt << endl;
    if ( cnt == 0 ) {
        cout << ( n + 1 ) * n / 2 << endl;
    } else if ( cnt == 1 ) {
        cout << (n - 1) * 2 << endl;
    } else if ( cnt == 2 ) {
        cout << 6 << endl;
    } else {
        cout << 0 << endl;
    }
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int t = 1;
    cin >> t;
    while (t--) solve();
    return 0;
}