#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 100;
const long long INF = 1e15;
char s[N];
long long dp[N][2];
int main() {
  long long t, n, a, b;
  scanf("%lld", &t);
  while (t--) {
    scanf("%lld%lld%lld", &n, &a, &b);
    scanf("%s", s + 1);
    for (int i = 0; i <= n; i++) {
      dp[i][0] = dp[i][1] = INF;
    }
    dp[0][0] = 0;
    for (int i = 1; i <= n; i++) {
      if (s[i] == '0') {
        dp[i][0] = min(dp[i - 1][0] + a + b, dp[i - 1][1] + a * 2 + b * 2);
        dp[i][1] = min(dp[i - 1][0] + a * 2 + b * 2, dp[i - 1][1] + a + b * 2);
      } else {
        dp[i][0] = INF;
        dp[i][1] = min(dp[i - 1][0] + a * 2 + b * 2, dp[i - 1][1] + a + b * 2);
      }
    }
    printf("%lld\n", dp[n][0] + b);
  }
  return 0;
}
