#include <iostream>
#include <string>

using namespace std;

int tab [500];

int main(int argc, char *argv[])
{
   int cases;
   cin >> cases;
   for ( int caseNo = 0; caseNo < cases; caseNo ++) 
   {
    int F;  // the amount of fuel to safely land
    string path;
    cin >> F >> path;
    
   
     // tab [i] - minimal cost of getting from location i to the base
    tab [ path.size()-1] = 0; // you are already at the base
    
    for ( int i = path.size() - 2; i >= 0; i -- ) 
    {
        int minCost = 500*500 + 101;
        for ( int j = i+1; j < path.size(); j ++)
        if ( path[j] != 'v' && (j-i)  * (j-i) + F + tab[j] < minCost)
            minCost = (j-i)  * (j-i) + F + tab[j];
        tab[i] = minCost;
    }
    
    cout << tab[0] << endl;
        
       
   }
   
   return 0;
}