#include <bits/stdc++.h> using namespace std; int main() { int tt; cin >> tt; while (tt--) { int n; cin >> n; string s; cin >> s; vector<int> cnt(2); for (int i = 0; i < n; i++) { cnt[s[i] - '0']++; } cnt[0] = min(cnt[0], cnt[1] + 1); cnt[1] = min(cnt[1], cnt[0] + 1); cout << cnt[0] + cnt[1] << endl; } return 0; }