#include <bits/stdc++.h>   using namespace std;   int main(int argc, char const *argv[]) {     int t, n, c_0, c_1, h;     string s;     cin >> t;     for (int i = 0; i < t; i++) {       cin >> n >> c_0 >> c_1 >> h;       cin >> s;       int sum = 0;       for (int j = 0; j < n; j++) {         sum += s[j] -  0 ;       }       if (c_0 - c_1 > h) {         sum = c_1 * n + (n - sum) * h;       } else if (c_1 - c_0 > h) {         sum = c_0 * n + sum * h;       } else         sum = c_1 * sum + (n - sum) * c_0;       cout << sum << endl;     }     return 0;   }   