#include <bits/stdc++.h>
using namespace std;
constexpr int MAXN = 2e5 + 42;
long long dp[MAXN][2];
void solve() {
  int N, A, B;
  string S;
  cin >> N >> A >> B >> S;
  fill(&dp[0][0], &dp[N + 1][0], 0);
  dp[0][0] = B;
  dp[0][1] = 1e17;
  for (int i = N - 1; i > 0; i--) {
    if (S[i] == '1') {
      S[i + 1] = '1';
    }
  }
  S += '0';
  for (int i = 1; i <= N; i++) {
    dp[i][1] = min(dp[i - 1][0] + A, dp[i - 1][1]) + A + 2 * B;
    if (S[i] == '0') {
      dp[i][0] = min(dp[i - 1][0], dp[i - 1][1] + A) + A + B;
    } else {
      dp[i][0] = 1e17;
    }
  }
  cout << dp[N][0] << endl;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int T;
  cin >> T;
  while (T--) {
    solve();
  }
  return 0;
}
