#include <bits/stdc++.h>
using namespace std;
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long t;
  cin >> t;
  while (t--) {
    long long n, a, b;
    cin >> n >> a >> b;
    long long dp[4][n + 1];
    string s;
    cin >> s;
    vector<long long> v(n + 1, 0);
    for (long long i = 1; i <= n; i++)
      if (s[i - 1] == '1') v[i] = 1;
    dp[0][0] = dp[1][0] = dp[2][0] = dp[3][0] = b;
    for (long long i = 1; i <= n; i++) {
      if (i == 1) {
        dp[0][i] = dp[0][0] + a + b;
        dp[1][i] = dp[0][0] + 2 * a + 2 * b;
        continue;
      }
      if (v[i] && v[i - 1])
        dp[0][i] = dp[1][i] = dp[1][i - 1] + a + 2 * b;
      else if (v[i] && !v[i - 1]) {
        dp[0][i] = dp[1][i] =
            min(dp[1][i - 1], dp[0][i - 2] + 2 * a + 2 * b) + a + 2 * b;
      } else if (!v[i] && !v[i - 1]) {
        dp[0][i] = min(dp[0][i - 1], dp[1][i - 1] + a) + b + a;
        dp[1][i] = min(dp[1][i - 1] + a, dp[0][i - 1] + 2 * a) + 2 * b;
      } else if (!v[i] && v[i - 1]) {
        dp[0][i] = dp[1][i - 1] + 2 * a + b;
        dp[1][i] = dp[1][i - 1] + 2 * b + a;
      }
    }
    cout << dp[0][n] << endl;
  }
  return 0;
}
