#include <bits/stdc++.h>
using namespace std;
long long bin_pow(long long a, long long b) {
  if (b == 0) return 1;
  if (b % 2 == 0) {
    long long t = bin_pow(a, b / 2);
    return t * t % 1000000007;
  } else
    return a * bin_pow(a, b - 1) % 1000000007;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  long long t, n, m, k, x = 0, y = 0, ans = 0, z = 0, sum = 0, l = 0, r = 0,
                        dp[200000][2], a, b;
  cin >> t;
  while (t--) {
    ans = 0;
    string s;
    cin >> n >> a >> b >> s;
    for (int i = 0; i < n; i++)
      for (int j = 0; j < 2; j++) dp[i][j] = LLONG_MAX / 4;
    dp[0][0] = a + b;
    dp[0][1] = a + b + a;
    for (int i = 1; i < n; i++) {
      if (s[i] == '0' && (i == n - 1 || (i != n - 1 && s[i + 1] == '0')))
        dp[i][0] = min(dp[i - 1][0] + a + b, dp[i - 1][1] + 2 * a + 2 * b);
      if (s[i] == '0')
        dp[i][1] = min(dp[i - 1][0] + 2 * a + b, dp[i - 1][1] + 2 * b + a);
      else
        dp[i][1] = dp[i - 1][1] + 2 * b + a;
    }
    ans = dp[n - 1][0];
    cout << ans + b;
    cout << "\n";
  }
  return 0;
}
