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#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;
typedef long long int lli;
int minOnes;

int ones(string s) {
    int res = 0;
    for (int i = 0; i < s.size(); i++) {
        if (s[i] == '1') {
            res++;
        }
    }
    return res;
}

void despread(string &s, vector<int> indices) {
    for (int index : indices) {
        s[index] = '0';
    }
}

vector<int> spread(string &s) {
    vector<int> indices;
    char prev = 'x';
    for (int i = 0; i < s.size(); i++) {
        char next = i < s.size()-1 ? s[i+1] : 'x';
        char curr = s[i];
        if (curr == '0' && (prev == '1' || next == '1')) {
            s[i] = '1';
            indices.push_back(i);
        }
        prev = curr;
    }
    return indices;
}

bool isOver(string s) {
    char prev = 'x';
    for (int i = 0; i < s.size(); i++) {
        char curr = s[i];
        char next = i < s.size() - 1 ? s[i+1] : 'x';
        if (curr == '0' && (prev == '1' || next == '1')) {
            return false;
        }
        prev = curr;
    }
    return true;
}

void minimum(string s, int xs, int ones) {
    if (isOver(s)) {
        minOnes = min(minOnes, ones);
        return;
    }
    char prev = 'x';
    for (int i = 0; i < s.size(); i++) {
        char curr = s[i];
        char next = i < s.size()-1 ? s[i+1] : 'x';
        if (curr == '0' && (prev == '1' || next == '1')) {
            s[i] = 'x';
            vector<int> indices = spread(s);
            minimum(s, xs + 1, ones + indices.size());
            despread(s, indices);
            s[i] = '0';
        }
        prev = curr;
    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    lli tests;
    cin >> tests;
    for (int t = 0; t < tests; t++) {
        lli n;
        cin >> n;
        string s;
        cin >> s;
        minOnes = INT32_MAX;
        int onesCount = ones(s);
        if (onesCount == 0) {
            cout << 0 << '\n';
            continue;
        }
        minimum(s, 0, onesCount);
        cout << minOnes << '\n';
    }
    return 0;
}