#include <bits/stdc++.h>
using namespace std;
const long long Max = 1e18;
void solve() {
  long long n, a, b;
  string s;
  cin >> n >> a >> b >> s;
  long long dp[n + 6][6];
  dp[0][0] = b;
  dp[0][1] = Max;
  for (int i = 1; i <= n; i++) {
    if (s[i - 1] == '1') {
      dp[i][0] = Max;
      dp[i][1] = dp[i - 1][1] + a + b + b;
    } else {
      dp[i][0] = min(dp[i - 1][0] + a + b, dp[i - 1][1] + a + a + b);
      dp[i][1] = min(dp[i - 1][1] + b + b + a, dp[i - 1][0] + a + a + b + b);
    }
  }
  cout << dp[n][0] << '\n';
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int t;
  cin >> t;
  while (t--) {
    solve();
  }
  return 0;
}
