#include <bits/stdc++.h>
using namespace std;
long long dp[2 * 100000 + 5][2];
long long a, b;
long long func(int i, int c) {
  if (dp[i][c] != -1) {
    return dp[i][c];
  }
  if (c == 0) {
    return dp[i][c] = min(func(i - 1, 0) + a + b, func(i - 1, 1) + 2 * a + b);
  } else {
    return dp[i][c] =
               min(func(i - 1, 0) + 2 * a + 2 * b, func(i - 1, 1) + a + 2 * b);
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long t, n;
  cin >> t;
  string z;
  while (t--) {
    cin >> n >> a >> b;
    cin >> z;
    for (int i = 0; i <= n + 1; i++) {
      dp[i][0] = -1;
      dp[i][1] = -1;
    }
    for (int i = 0; i < n; i++) {
      if (z[i] == '1') {
        dp[i][0] = (1ll << 60) - 1;
        dp[i + 1][0] = (1ll << 60) - 1;
      }
    }
    dp[0][1] = (1ll << 60) - 1;
    dp[n][1] = (1ll << 60) - 1;
    dp[0][0] = b;
    cout << func(n, 0) << "\n";
  }
  return 0;
}
