#include <bits/stdc++.h>
const int inf = 0x3f3f3f3f;
const int inn = 0x80808080;
using namespace std;
int main() {
  int T;
  scanf("%d", &T);
  while (T--) {
    long long n, a, b;
    cin >> n >> a >> b;
    string s;
    cin >> s;
    long long num = 0;
    long long i = 0;
    while (i < n) {
      while (i < n && s[i] == '0') i++;
      int cnt = 0;
      while (i < n && s[i] == '1') cnt++, i++;
      if (cnt) num += cnt + 1;
    }
    long long ans = (long long)a * n + b * (n + 1) + num * b;
    if (!num) {
      cout << ans << endl;
      continue;
    }
    ans += a * 2;
    int st = 0;
    while (s[st] == '0') st++;
    int ed = n - 1;
    while (s[ed] == '0') ed--;
    i = st;
    while (i < ed) {
      while (i < ed && s[i] == '1') i++;
      int cnt = 0;
      while (i < ed && s[i] == '0') cnt++, i++;
      if (cnt) ans += min(a * 2, b * (cnt - 1));
    }
    cout << ans << endl;
  }
  return 0;
}
