#include <bits/stdc++.h>
using namespace std;
long long t, n, a, b;
string s;
int main() {
  ios_base::sync_with_stdio(false);
  cin >> t;
  while (t--) {
    cin >> n >> a >> b;
    cin >> s;
    long long ans = (n + 1) * (b + a) - a;
    long long curh = 1;
    for (int i = 0; i < n; i++) {
      if (s[i] == '1') {
        if (curh == 2)
          ans += b;
        else
          ans += a + b;
        curh = 2;
      } else {
        if (curh == 1) continue;
        int j = i;
        while (j < n && s[j] == '0') j++;
        long long sinexise = (j - i) * b;
        long long kateva = 2 * a + b;
        if (j == n) {
          kateva -= a;
          sinexise = 1e9 + 7;
        }
        if (sinexise > kateva)
          ans += kateva;
        else
          ans += sinexise;
        i = j - 1;
        curh = 2;
      }
    }
    cout << ans << "\n";
  }
  return 0;
}
