#include <bits/stdc++.h>
inline long long read() {
  long long sign = 1;
  long long x = 0;
  char ch;
  while (!isdigit(ch = getchar()))
    if (ch == '-') sign = -1;
  while (isdigit(ch)) x = x * 10 + ch - '0', ch = getchar();
  return x * sign;
}
inline void wonl() { putchar('\n'); }
inline void ww(long long k) {
  if (k < 0) putchar('-'), k *= -1;
  char ch[20];
  int num = 0;
  while (k) ch[++num] = k % 10, k /= 10;
  if (num == 0) ch[++num] = 0;
  while (num) putchar(ch[num--] + '0');
}
using namespace std;
const int N = 2e5 + 4;
template <typename T, typename... V>
inline void wonl(T t, V... v) {
  ww(t);
  if (sizeof...(v)) putchar(' ');
  wonl(v...);
}
void solve() {
  int n;
  string s;
  cin >> n >> s;
  vector<int> a;
  for (int i = 0; i < n;) {
    int tmp = 0;
    char c = s[i];
    while (i < n && s[i] == c) tmp++, i++;
    a.push_back(tmp);
  }
  int len = a.size(), mx = 0, del = 0;
  for (int i = 0; i < a.size(); i++) {
    mx += min(a[i] - 1, i - del + 1);
    del += min(a[i] - 1, i - del + 1);
  }
  if (len <= mx) {
    cout << len << endl;
    return;
  }
  int ans = mx;
  ans += ((len - mx + 2 - 1) / 2);
  cout << ans << endl;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int t = 1;
  cin >> t;
  while (t--) {
    solve();
  }
  return 0;
}
