#include <bits/stdc++.h>
using namespace std;
long long int n, a, b;
char s[200005];
long long int dp[200005][2];
int main() {
  int _;
  scanf("%d", &_);
  while (_--) {
    scanf("%lld%lld%lld%s", &n, &a, &b, s + 1);
    dp[0][0] = b;
    dp[0][1] = 1e14;
    for (int i = 1; i <= n; i++) {
      if (s[i] == '1' || s[i + 1] == '1')
        dp[i][0] = 1e14,
        dp[i][1] = min(dp[i - 1][0] + a + a + b + b, dp[i - 1][1] + a + b + b);
      else
        dp[i][0] = min(dp[i - 1][0] + a + b, dp[i - 1][1] + a + a + b),
        dp[i][1] = min(dp[i - 1][0] + a + a + b + b, dp[i - 1][1] + a + b + b);
    }
    printf("%lld\n", dp[n][0]);
  }
  return 0;
}
