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