#include <bits/stdc++.h>
using namespace std;
void faster() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
}
const long long INF = 1e18;
const long double PI = acos(-1);
const long long MAXN = 2e5 + 2e2;
const long long dx[4] = {-1, 0, 0, 1};
const long long dy[4] = {0, -1, 1, 0};
long long T, n, a, b, dp[MAXN][2];
string s;
void solve() {
  cin >> n >> a >> b;
  cin >> s;
  for (int i = 0; i <= n; ++i) dp[i][0] = dp[i][1] = INF;
  dp[0][0] = b;
  dp[0][1] = INF;
  for (int i = 0; i < n; ++i) {
    if (s[i] == '0') {
      dp[i + 1][0] = min(dp[i][0] + a + b, dp[i][1] + 2 * a + b);
      dp[i + 1][1] = min(dp[i][1] + a + 2 * b, dp[i][0] + 2 * a + 2 * b);
    } else {
      dp[i + 1][1] = dp[i][1] + a + 2 * b;
    }
  }
  cout << dp[n][0] << '\n';
}
int main() {
  faster();
  cin >> T;
  while (T--) {
    solve();
  }
  return 0;
}
