#include <bits/stdc++.h>
using namespace std;
long long int mod = 1000000007;
long long int MAX = 1e18;
int main() {
  int t;
  cin >> t;
  while (t--) {
    int n, a, b;
    cin >> n >> a >> b;
    string s;
    cin >> s;
    int v[n];
    for (int i = 0; i < n; i++) v[i] = s[i] - 48;
    long long int dp[n][2];
    dp[0][0] = a + 2 * b;
    dp[0][1] = 2 * a + 3 * b;
    for (int i = 1; i < n; i++) {
      if (v[i] == 0) {
        dp[i][0] = min(dp[i - 1][0] + a + b, dp[i - 1][1] + 2 * a + 2 * b);
        dp[i][1] = min(dp[i - 1][1] + a + 2 * b, dp[i - 1][0] + 2 * a + 2 * b);
      }
      if (v[i] == 1) {
        dp[i][1] = min(dp[i - 1][0] + 2 * a + 2 * b, dp[i - 1][1] + a + 2 * b);
        dp[i][0] = MAX;
      }
    }
    cout << dp[n - 1][0] << endl;
  }
  return 0;
}
