#include <bits/stdc++.h>
using namespace std;
int MOD = 1e9 + 7;
long long int power(long long int a, long long int b) {
  long long int res = 1;
  a = a % MOD;
  while (b > 0) {
    if (b & 1) {
      res = (res * a) % MOD;
      b--;
    }
    a = (a * a) % MOD;
    b >>= 1;
  }
  return res;
}
long long int fermat_inv(long long int y) { return power(y, MOD - 2); }
long long int gcd(long long int a, long long int b) {
  return (b == 0) ? a : gcd(b, a % b);
}
long long int min(long long int a, long long int b) { return (a > b) ? b : a; }
long long int max(long long int a, long long int b) { return (a > b) ? a : b; }
bool prime[1000001];
vector<int> primes;
void SieveOfEratosthenes(int n) {
  memset(prime, true, sizeof(prime));
  for (int p = 2; p * p <= n; p++) {
    if (prime[p] == true) {
      for (int i = p * p; i <= n; i += p) prime[i] = false;
    }
  }
  for (int p = 2; p < 1000001; p++)
    if (prime[p]) primes.push_back(p);
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int t = 1;
  cin >> t;
  while (t--) {
    long long int n, a, b;
    string s;
    cin >> n >> a >> b >> s;
    long long int cost = n * a + (n + 1) * b;
    vector<int> v;
    long long int j = 1;
    for (int i = 1; i < n; i++) {
      if (s[i] == s[i - 1])
        j++;
      else {
        v.push_back(j);
        j = 1;
      }
    }
    if (v.empty()) {
      cout << cost << '\n';
      continue;
    }
    v.erase(v.begin());
    cost += 2 * a;
    for (int i = 0; i < v.size(); i++) {
      if (i % 2 == 0)
        cost += (long long int)(v[i] + 1) * b;
      else {
        if (2 * a <= (long long int)(v[i] - 1) * b)
          cost += 2 * a;
        else
          cost += (long long int)(v[i] - 1) * b;
      }
    }
    cout << cost << '\n';
  }
}
