#include <bits/stdc++.h>
using namespace std;
const int N = 1000005;
long long modd = 998244353;
vector<bool> isprime(N);
vector<int> primes;
void seive() {
  isprime[0] = false;
  isprime[1] = false;
  for (int i = 2; i <= 1e6; i++) {
    isprime[i] = true;
  }
  for (int i = 2; i * i <= 1e6; i++) {
    if (isprime[i]) {
      for (int j = i * i; j <= 1e6; j += i) {
        isprime[j] = false;
      }
    }
  }
  for (int i = 2; i < 1e6; i++) {
    if (isprime[i]) {
      primes.push_back(i);
    }
  }
}
void Reverse_Matrix() {
  long long n, a, b;
  cin >> n >> a >> b;
  string s;
  cin >> s;
  int cnt = 0;
  long long dp1[n + 1], dp0[n + 1];
  dp1[0] = 0;
  for (int i = 1; i < n - 1; i++) {
    dp1[i] = a * i + (i + 1) * b * 2;
  }
  dp0[0] = 0;
  dp0[1] = a;
  for (int i = 2; i < n + 1; i++) {
    long long val = (i - 1) * b + (i + 2) * a;
    val = min(val, i * a + (i - 1) * 2 * b);
    dp0[i] = val;
  }
  int i = 0;
  while (s[i] == '0' && i < n) {
    cnt++;
    i++;
  }
  if (i >= n) {
    long long anss = 0;
    cout << cnt * a + cnt * b + b << endl;
    return;
  }
  long long ans = (cnt + 1) * a + b * cnt;
  int j = n - 1;
  cnt = 0;
  while (s[j] == '0' && j > i) {
    j--;
    cnt++;
  }
  ans += (cnt + 1) * a + b * cnt;
  while (i <= j) {
    cnt = 0;
    while (s[i] == '1' && i <= j) {
      i++;
      cnt++;
    }
    ans += dp1[cnt];
    cnt = 0;
    while (s[i] == '0' && i <= j) {
      i++;
      cnt++;
    }
    ans += dp0[cnt];
  }
  cout << ans << endl;
}
int main() {
  ios_base::sync_with_stdio(false);
  int TEST = 1;
  cin >> TEST;
  while (TEST--) {
    Reverse_Matrix();
  }
}
