#include <bits/stdc++.h>
using namespace std;
#define ls u << 1
#define rs u << 1 | 1
#define LL long long
#define int long long
#define PII pair <int, int>
#define fi first
#define se second
#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define lb lower_bound
#define ub upper_bound
#define i128 __int128
#define pcnt(x) __builtin_popcount(x)
#define mem(a,goal) memset(a, (goal), sizeof(a))
#define rep(x,start,end) for(int x = (start) - ((start) > (end)); x != (end) - ((start) > (end)); ((start) < (end) ? x ++ : x --))
#define aLL(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
const int INF = 998244353;
const int mod = 1e9 + 7;
const int N = 100010;
void solve()
{
    int n;
    cin >> n;
    string s;
    cin >> s;
    int cnt0 = 0, cnt1 = 0;
    int ans = 0;
    s = " " + s;
    for(int i = 1; i <= n; ++ i)
    {
        if(s[i] == '0' || s[i] == '?')
        {
            cnt0 ++;
            ans += cnt1;
        }
        else cnt1 ++;
    }
    int res = ans;
    cnt0 = n - cnt1;
    cnt1 = 0;
    for(int i = 1; i <= n; ++ i)
    {
        if(s[i] == '1') cnt1 ++;
        if(s[i] == '0') cnt0 --;
        if(s[i] == '?')
        {
            cnt0 --;
            ans = res - cnt1 + cnt0;
            res = max(res, ans);
            cnt1 ++;
        }
      /*
          if(s[i] == '?')
        {
            cnt0 --;
            ans = res - cnt1 + cnt0;
            cnt1 ++;
            if(ans > res) res = ans;
            else
            {
                cnt0 ++;
                cnt1 --;
            }
        }
      */
    }
    cout << res << '\n';
}
signed main()
{
    int t = 1;
    cin >> t;
    while (t --) solve();
    return 0;
}