#include <bits/stdc++.h>
using namespace std;
#define int              long long int
#define double           long double
#define print(a)         for(auto x : a) cout << x << " "; cout << endl


const int M = 1000000007;
const int N = 3e5+9;
const int INF = 2e9+1;
const int LINF = 2000000000000000001;

inline int power(int a, int b, int mod=M) {
    int x = 1;
    a %= mod;
    while (b) {
        if (b & 1) x = (x * a) % mod; 
        a = (a * a) % mod;
        b >>= 1;
    }
    return x;
}


//_ ***************************** START Below *******************************




string a;

int consistency(int n, int k){

	vector<vector<vector<int>>> dp(n, vector<vector<int>>(n, vector<int>(k+1, 1)));
	
	for(int p=0; p<=k; p++){
    	for(int gap=0; gap<n; gap++){
    	    for(int i=0, j=gap; j<n; i++, j++){
    	        if(gap == 0){
    	            dp[i][j][p] = 1;
    	        }
    	        else if(gap == 1){
    	            int d1 = abs(a[i] - a[j]);
    	            int d = min(d1, 26-d1);

    	            if(p>=d){
    	                dp[i][j][p] = 2;
    	            }
    	            else{
    	                dp[i][j][p] = 1;
    	            }

    	        }
    	        else{
    	            int d1 = abs(a[i] - a[j]);
    	            int d = min(d1, 26-d1);
    	            
    	            dp[i][j][p] = max(dp[i+1][j][p], dp[i][j-1][p]);
    	            
    	            if(a[i] == a[j]){
    	                dp[i][j][p] = max(dp[i][j][p], 2 + dp[i+1][j-1][p]);
    	            }
    	            else if(p-d>=0){
    	                dp[i][j][p] = max(dp[i][j][p], 2 + dp[i+1][j-1][p-d]);
    	            }
    	        }
    	    }
    	}
    	
	}
	
    return dp[0][n-1][k];

}















int practice(int n, int k){


    return 0;
}





void solve() {
    
    cin >> a;
    int n = a.size();
    
    int k;
    cin >> k;
    
    cout << consistency(n, k) << endl;


}





int32_t main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
    }

    return 0;
}