#include <bits/stdc++.h>
using namespace std;
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  long long t;
  cin >> t;
  while (t--) {
    long long n, a, b;
    cin >> n >> a >> b;
    string s;
    cin >> s;
    for (long long i = 1; i < s.length() - 1; i++) {
      if (s[i] == '0') {
        if (s[i + 1] == '1' && s[i - 1] == '1') s[i] = '1';
      }
    }
    long long c = -1;
    long long ans = 0;
    vector<long long> v;
    for (long long i = 0; i < s.length(); i++) {
      char ch = s[i];
      long long d = 0;
      while (s[i] == ch && i < s.length()) {
        i++;
        d++;
      }
      i--;
      ans += d * a;
      if (ch == '0')
        ans += (d + 1) * b;
      else
        ans += (d + 1) * 2 * b;
      if (ch == '0') v.push_back(d);
      c++;
    }
    ans += c * (a - b);
    long long p = v.size();
    if (p > 2) {
      for (long long i = 1; i < p - 1; i++) {
        if (2 * a > b * (v[i] - 1)) {
          ans -= 2 * a;
          ans += b * (v[i] - 1);
        }
      }
    }
    cout << ans << endl;
  }
  return 0;
}
