#include <bits/stdc++.h>
using namespace std;
const long long DIM = 100;
const long long INF = 1000000007;
long long n, m, k;
long long a, b, c, d;
long long ans;
long long v[DIM][DIM];
long long v1[DIM][DIM];
long long l, r;
string s;
long long mas[DIM];
long long used[DIM];
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long t;
  cin >> t;
  for (long long ka = 1; ka <= t; ka++) {
    cin >> n;
    cin >> a >> b;
    cin >> s;
    long long last = -INF, dlina = 0, ans = 0;
    for (long long i = 0; i < n; i++) {
      if (s[i] == '0' && dlina != 0) {
        if (last != -INF)
          ans += min(2 * a, (i - dlina - last - 1) * b);
        else
          ans += 2 * a;
        ans += (dlina + 1) * b;
        last = i;
        dlina = 0;
      }
      if (s[i] == '1') dlina++;
    }
    ans += n * a + n * b + b;
    cout << ans << "\n";
  }
  return 0;
}
