#include <bits/stdc++.h>
using namespace std;
long long int dp[200005][2];
void solve() {
  long long int n, a, b;
  cin >> n >> a >> b;
  string s;
  cin >> s;
  dp[1][0] = 0;
  dp[1][1] = 1e18;
  for (long long int i = 2; i <= n; i++) {
    if (s[i - 1] == '1')
      dp[i][0] = 1e18;
    else
      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);
  }
  cout << dp[n][0] + a + 2 * b << endl;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  int t = 1;
  cin >> t;
  for (int i = 0; i < t; i++) {
    solve();
  }
  return 0;
}
