#include <bits/stdc++.h>
using ll = long long;

const int maxn = 100005;

int n, c1[3], c2[3], ans;
std::string s1, s2, t1, t2;
void solve() {
  std::cin >> n >> s1 >> s2 >> t1 >> t2;
  ++n, s1.push_back('0'), s2.push_back('0'), t1.push_back('0'), t2.push_back('0');
  c1[0] = c1[1] = c1[2] = c2[0] = c2[1] = c2[2] = 0;
  ans = 0;
  for (int i = 0, j = 0; i < n || j < n;) {
    int p1 = i, p2 = j;
    for (; t1[p1] != '0'; ++p1) ++c1[s1[p1] - '0'];
    for (; t2[p2] != '0'; ++p2) ++c2[s2[p2] - '0'];
    if (p1 < p2) {
      ++c1[s1[p1] - '0'];
      int w0 = std::min(c1[0], c2[0]), w1 = std::min(c1[1], c2[1]);
      ans += w0 + w1;
      c2[0] -= w0, c2[1] -= w1;
      if (c2[0] > 0) c2[0] -= (c1[0] + c1[1]) - (w0 + w1);
      else c2[1] -= (c1[0] + c1[1]) - (w0 + w1);
      c1[0] = c1[1] = c1[2] = 0;
      i = p1 + 1, j = p2;
    } else if (p1 > p2) {
      ++c2[s2[p2] - '0'];
      int w0 = std::min(c1[0], c2[0]), w1 = std::min(c1[1], c2[1]);
      ans += w0 + w1;
      c1[0] -= w0, c1[1] -= w1;
      if (c1[0] > 0) c1[0] -= (c2[0] + c2[1]) - (w0 + w1);
      else c1[1] -= (c2[0] + c2[1]) - (w0 + w1);
      c2[0] = c2[1] = c2[2] = 0;
      i = p1, j = p2 + 1;
    } else {
      if (s1[p1] == s2[p2]) ++ans;
      int w0 = std::min(c1[0], c2[0]), w1 = std::min(c1[1], c2[1]);
      ans += w0 + w1;
      c1[0] = c1[1] = c1[2] = c2[0] = c2[1] = c2[2] = 0;
      i = p1 + 1, j = p2 + 1;
    }
    // std::clog << p1 << ' ' << p2 << ' ' << ans << std::endl;
    // std::clog << c1[0] << ' ' << c1[1] << ' ' << c2[0] << ' ' << c2[1] << std::endl;
  }
  std::cout << ans - 1 << '\n';
}

int main() {
  std::freopen("edit.in", "r", stdin);
  std::freopen("edit.out", "w", stdout);
  std::ios::sync_with_stdio(false);
  std::cin.tie(0);
  std::cout.tie(0);

  int T;
  std::cin >> T;
  while (T--) solve();

  std::cout.flush();
  return 0;
}