#include <bits/stdc++.h>
using namespace std;
long long int T, N, A, B, ans;
string S;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cin >> T;
  while (T--) {
    cin >> N >> A >> B;
    cin >> S;
    ans = B;
    bool ch = false, h = false;
    long long int cost1 = 0, cost2 = 0;
    for (int j = 0; j < S.size(); j++) {
      if (S[j] == '1' && !ch) {
        ch = true;
        h = true;
        ans += cost1 + A + B + A + 2 * B;
        cost1 = 0;
        cost2 = 0;
      } else if (S[j] == '1' && ch) {
        if (h) {
          ans += A + 2 * B;
        } else {
          cost1 += A + B;
          ans += min(cost1, cost2);
          cost1 = 0;
          cost2 = 0;
          ans += A + 2 * B;
        }
        h = true;
      } else if (S[j] == '0') {
        if (h) {
          cost1 += (long long int)2 * A + B;
          cost2 += A + 2 * B;
        } else {
          cost1 += A + B;
          cost2 += A + 2 * B;
        }
        h = false;
      }
    }
    ans += cost1;
    cout << ans << "\n";
  }
  return 0;
}
