#include <bits/stdc++.h>
const long long INF = 1e18;
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long t;
  cin >> t;
  for (long long i = 0; i < t; i++) {
    long long n, a, b;
    cin >> n >> a >> b;
    long long ans = 0;
    string s;
    cin >> s;
    vector<vector<long long>> dp(n, vector<long long>(2));
    dp[0][1] = b + (2 * a + 2 * b);
    dp[0][0] = b + a + b;
    for (long long i = 1; i < n; i++) {
      if (s[i] == '1') {
        dp[i][1] = dp[i - 1][1] + a + 2 * b;
        dp[i][0] = INF;
      } else {
        dp[i][1] = min(dp[i - 1][1] + a + 2 * b, dp[i - 1][0] + 2 * a + 2 * b);
        dp[i][0] = min(dp[i - 1][1] + 2 * a + b, dp[i - 1][0] + a + b);
      }
    }
    cout << dp[n - 1][0] << endl;
  }
  return 0;
}
