#include <iostream>
#include <stdio.h>
#include <string>
#include <memory.h>
#include <set>
#include <map>
#include <vector>
#include <queue>
#include <time.h>
#include <assert.h>
#include <cmath>
#include <stack>
#include <string.h>
#include <sstream>
#include <algorithm>
using namespace std;
typedef long long ll;
const int N = 300;
string s;
int n, k, dp[N][N][N + 1];
int calc(int i, int j, int k) {
	if (k < 0)
		return -1e9;
	if (i >= j)
		return i==j;
	int &ret = dp[i][j][k];
	if (ret != -1)
		return ret;
	ret = max(calc(i + 1, j, k), calc(i, j - 1, k));
	if (s[i] == s[j])
		ret = max(ret, calc(i + 1, j - 1, k) + 2);
	ret = max(ret, calc(i + 1, j - 1, k - 1) + 2);
	return ret;
}
int main()
{
	cin >> s;
	n = s.size();
	cin >> k;
	memset(dp, -1, sizeof(dp));
	cout << calc(0, n - 1, k) << endl;
	return 0;
}