#include <bits/stdc++.h>
using namespace std;
#define SC               scanf
#define PF               printf
#define ull              unsigned long long
#define ld               long double
#define F                first
#define S                second
#define pb               push_back
#define sort_a(a)        sort(a.begin(),a.end());
#define sort_d(a)        sort(a.rbegin(),a.rend());
#define READ(f)          freopen(f, "r", stdin)
#define WRITE(f)         freopen(f, "w", stdout)
#define rev(s)           reverse(s.begin(),s.end())
#define P(ok)            cout << (ok ? "YES\n": "NO\n")
#define __Heart__              ios_base :: sync_with_stdio(false); cin.tie(NULL);
#define ll long long
typedef pair< ll , ll>                   PII;
const int sz= 5e3 + 5 ;


void solve()
{
   int make_A[sz] , make_B[sz] , make_C[sz] , substringCost[sz] , n , k , Ans = 0;
   string s ;
    cin >> n >> k >> s ;
    for(int i = 0 ; i < n ; i++){
        make_A[i] = (122 - s[i] + 1) % 26 ;
        make_B[i] = (122 - s[i] + 2) % 26 ;
        make_C[i] = (122 - s[i] + 3) % 26 ;
    }
    for(int i = 0 ; i <= n - 3 ; i++) {
       substringCost[i] = make_A[i] + make_B[i + 1] + make_C[i + 2] ;
    }
  vector<int> dp(k + 1, 0);
     dp[0] = 0;
    for (int i = 0; i <= n - 3  ; i++) {
        for(int j = k ; j >= substringCost[i] ; j--){
            dp[j] = max(dp[j] , dp[j - substringCost[i]] + 1) ;
        }

    }
    cout << dp[k] << "\n" ;

}
int main()
{
     __Heart__
     int t ; cin >> t ; while(t--) solve() ;
}