#include<bits/stdc++.h>
#define forn(i,n) for(int i = 0; i < n; i++)
#define forr(i,a,n) for(int i = a; i <= n; i++)
#define fi first
#define se second
#define lli long long int
#define all(v) v.begin(), v.end()
using namespace std;
typedef vector<int> vi;
typedef pair<int,int> pii;
int tt, n, A, B;
int main() {
	cin >> tt;
	while(tt--) {
		cin >> n >> A >> B;
		string s;
		vi a(n);
		int unos = 0, ceros = 0;
		cin >> s;
		int blck = 1;
		bool par = false;
		forn(i,n) {
			if(i == 0) par = s[i]-'0';
			if((bool)(s[i] - '0') == par) continue;
			else {
				blck++;
				par = s[i] - '0';
			}
		}
		int ans = n*A + max(n*B, (blck/2+1)*B);
		cout << ans << '\n';
	}
	return 0;
}
