#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int t, n, a, b, h, res, l, ca, cb;
  string s;
  cin >> t;
  while (t--) {
    cin >> n >> a >> b;
    cin >> s;
    h = 1;
    res = 0;
    res += n * a;
    res += (n + 1) * b;
    for (int i = 0; i < n; i++) {
      if (s[i] == '1' && h == 1) {
        res += a + 2 * b;
        h = 2;
      } else if (s[i] == '1' && h == 2) {
        res += b;
      } else if (s[i] == '0' && h == 2) {
        if (i == n - 1) {
          res += a;
          h = 1;
          continue;
        }
        l = 0;
        for (l = i; l < n; l++) {
          if (s[l] == '1') {
            break;
          }
        }
        if (l == n) {
          res += a;
          h = 1;
          continue;
        }
        ca = 2 * a;
        cb = (l - i - 1) * b;
        if (ca < cb) {
          res += ca;
          h = 2;
        } else {
          res += cb;
        }
        res += 2 * b;
        i = l;
      }
    }
    cout << res << endl;
  }
  return 0;
}
