#include <bits/stdc++.h>
using namespace std;
long long t, n, a, b;
string s;
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> t;
  while (t--) {
    cin >> n >> a >> b;
    cin >> s;
    vector<pair<long long, long long> > ans;
    long long l = 0;
    while (l < n) {
      long long r = l;
      while (r < n && s[l] == s[r]) r++;
      ans.emplace_back(r - l, s[l] - '0');
      l = r;
    }
    long long cnt = 2 * b;
    cnt += n * a;
    if (ans.size() != 1) cnt += 2 * a;
    for (long long i = 0; i < ans.size(); i++) {
      if (ans[i].second == 1)
        cnt += 2 * b * (ans[i].first + 1);
      else {
        if (i == 0 || i == ans.size() - 1)
          cnt += b * (ans[i].first - 1);
        else
          cnt +=
              min(b * (ans[i].first - 1) + 2 * a, 2 * b * (ans[i].first - 1));
      }
    }
    cout << cnt << endl;
  }
}
