#include<bits/stdc++.h>
#define endl '\n'
#define ll long long
#define pii pair<int, int>
const ll inf = 1145141919810;
using namespace std;
const int N = 2e5 + 7;
ll c[N], n;
void add(int x, ll y){
    for(; x <= n; x += (x & -x)) c[x] += y;
}
void slv(){
    cin >> n;
    string s;
    cin >> s;
    s = "0" + s;
    ll ans = 0;
    for(int i = 1; i <= n; ++i){
        if(c[i] == 0 && s[i] == '1') {
            ans ++ ;
            add(i, (n - i + 1));
        }else if(c[i] && s[i] == '0'){
            ans ++ ;
            add(i, -c[i]);
        }
    }
    for(int i = 0; i <= n; ++i) c[i] = 0;
    cout << ans << endl;
}

int main(){
    ios::sync_with_stdio(0), cin.tie(0);
    int _ = 1;
    cin >> _;
    while(_--) slv();
    return 0;
}
/*
3
5
10110
5
00000
5
11111
 */