#include <bits/stdc++.h>
using namespace std;
long long dp[2][200000 + 500];
long long a, b;
int n;
char s[200000 + 500];
inline long long solve(int i, int h) {
  if (i == n) {
    if (h == 0)
      return a + b;
    else
      return 2 * a + b;
  }
  long long &ret = dp[h][i];
  if (ret != -1) return ret;
  ret = 1e18 + 1;
  if (h == 0) {
    if (s[i + 1] == '1') {
      ret = min(ret, solve(i + 1, 1) + 2ll * (a + b));
    } else {
      ret = min(ret, solve(i + 1, 1) + 2ll * (a + b));
      ret = min(ret, solve(i + 1, 0) + (a + b));
    }
  } else {
    if (s[i + 1] == '1') {
      ret = min(ret, solve(i + 1, 1) + 2ll * b + a);
    } else {
      ret = min(ret, solve(i + 1, 1) + 2ll * b + a);
      if (s[i] == '0') ret = min(ret, solve(i + 1, 0) + 2ll * a + b);
    }
  }
  return ret;
}
int main() {
  int t;
  scanf("%d", &t);
  while (t--) {
    scanf("%d", &n);
    scanf("%lld %lld", &a, &b);
    scanf("%s", s + 1);
    for (int i = 0; i <= n; i++) dp[0][i] = dp[1][i] = -1;
    printf("%lld\n", solve(1, 0) + b);
    ;
  }
  return 0;
}
