#include <bits/stdc++.h>
using namespace std;
int main() {
  cin.tie(0);
  cout.tie(0);
  ios_base::sync_with_stdio(0);
  ;
  int T;
  cin >> T;
  while (T--) {
    int n;
    string s;
    cin >> n;
    cin >> s;
    int arr[200002];
    int cnt = 1;
    int idx = 1;
    char x = s[0];
    for (int i = (1); i <= (n - 1); i++) {
      if (s[i] == x) {
        cnt++;
      } else if (s[i] != x) {
        x = s[i];
        arr[idx] = cnt;
        idx++;
        cnt = 1;
      }
    }
    arr[idx] = cnt;
    arr[idx + 1] = 2;
    int ans = 0;
    int idx2 = 1;
    int usable_idx = 1;
    int len = idx;
    while (arr[usable_idx] == 1) {
      usable_idx++;
    }
    while (idx2 <= len) {
      if (usable_idx > len) {
        ans += (len - idx2) / 2 + 1;
        break;
      }
      if (arr[idx2] == 1) {
        arr[usable_idx]--;
        if (arr[usable_idx] == 1) {
          usable_idx++;
          while (arr[usable_idx] == 1) {
            usable_idx++;
          }
        }
      } else if (arr[idx2] != 1) {
        if (usable_idx == idx2) {
          usable_idx++;
          while (arr[usable_idx] == 1) {
            usable_idx++;
          }
        }
      }
      idx2++;
      ans++;
    }
    cout << ans << "\n";
  }
  return 0;
}
