#include <bits/stdc++.h>
using namespace std;
#pragma warning(disable : 4996)
const int INF = 1e9 + 1;
const long long LINF = 1e18 + 1;
const int MOD = 1000000007;
int T;
int n, a, b;
int arr[200001];
long long dp[200001][2];
int main() {
  scanf("%d", &T);
  while (T--) {
    scanf("%d %d %d", &n, &a, &b);
    for (int i = 0; i < n; i++) {
      scanf("%1d", arr + 1 + i);
    }
    dp[0][1] = LINF;
    dp[0][0] = b;
    for (int i = 1; i <= n; i++) {
      if (arr[i] == 1) {
        dp[i][0] = LINF;
        dp[i][1] = dp[i - 1][1] + 2 * b + a;
      } else {
        dp[i][0] = min(dp[i - 1][0] + a, dp[i - 1][1] + 2 * a) + b;
        dp[i][1] = min(dp[i - 1][0] + 2 * a, dp[i - 1][1] + a) + 2 * b;
      }
    }
    printf("%lld\n", dp[n][0]);
  }
  return 0;
}
