#include <bits/stdc++.h>
using namespace std;

string s, rs;
int n, k;
vector<vector<vector<int>>> dp;

int solve();

int main() {
  cin >> s >> k;
  n = s.size();
  rs = s;
  reverse(rs.begin(), rs.end());
  cout << solve() << endl;
  return 0;
}

int solve() {
  int res = 0;
  dp.assign(n + 1, vector(n + 1, vector<int>(k + 1, 0)));
  for (int i = 0; i < n; ++i)
    for (int j = 0; j < n; ++j)
      for (int l = 0; l <= k; ++l) {
        dp[i + 1][j + 1][l] = max(dp[i + 1][j][l], dp[i][j + 1][l]);
        if (s[i] == rs[j])
          dp[i + 1][j + 1][l] = max(dp[i + 1][j + 1][l], dp[i][j][l] + 1);
        else if (l != 0)
          dp[i + 1][j + 1][l] = max(dp[i + 1][j + 1][l], dp[i][j][l - 1] + 1);
        else
          dp[i + 1][j + 1][l] = max(dp[i + 1][j + 1][l], dp[i][j][l]);
      }
  for (int i = 0; i <= n; ++i)
    for (int j = 0; j <= n; ++j)
      for (int l = 1; l <= k; ++l)
        dp[i][j][l] = max(dp[i][j][l], dp[i][j][l - 1]);
  for (int i = 0; i <= n; ++i) {
    // even
    res = max(res, dp[i][n - i][k] * 2);
    // odd
    if (i > 0) res = max(res, dp[i - 1][n - i][k] * 2 + 1);
  }
  return res;
}
//Author:xht37
#include <bits/stdc++.h>

#define ui unsigned int
#define ll long long
#define ul unsigned ll
#define ld long double

#define pi pair <int, int>
#define fi first
#define se second
#define mp make_pair

#define ls (p << 1)
#define rs (ls | 1)
#define md ((t[p].l + t[p].r) >> 1)

#define vi vector <int>
#define pb push_back
#define pq priority_queue

#define dbg(x) cerr << #x" = " << (x) << endl
#define debug(...) fprintf(stderr, __VA_ARGS__)

#define fl(x) freopen(x".in", "r", stdin), freopen(x".out", "w", stdout)

using namespace std;

namespace io {
	const int SI = 1 << 21 | 1;
	char IB[SI], *IS, *IT, OB[SI], *OS = OB, *OT = OS + SI - 1, c, ch[100];
	int f, t;
	#define gc() (IS == IT ? (IT = (IS = IB) + fread(IB, 1, SI, stdin), IS == IT ? EOF : *IS++) : *IS++)
	inline void flush() {
		fwrite(OB, 1, OS - OB, stdout), OS = OB;
	}
	inline void pc(char x) {
		*OS++ = x;
		if (OS == OT) flush();
	}

	template <class I>
	inline void rd(I &x) {
		for (f = 1, c = gc(); c < '0' || c > '9'; c = gc()) if (c == '-') f = -1;
		for (x = 0; c >= '0' && c <= '9'; x = (x << 3) + (x << 1) + (c & 15), c = gc());
		x *= f;
	}
	template <class I>
	inline void rd(I &x, I &y) {
		rd(x), rd(y);
	}
	template <class I>
	inline void rd(I &x, I &y, I &z) {
		rd(x), rd(y), rd(z);
	}
	template <class I>
	inline void rda(I *a, int n) {
		for (int i = 1; i <= n; i++) rd(a[i]);
	}
	inline void rdc(char &c) {
		for (c = gc(); c < 33 || c > 126; c = gc());
	}
	inline void rds(char *s, int &n) {
		for (c = gc(); c < 33 || c > 126; c = gc());
		for (n = 0; c >= 33 && c <= 126; s[++n] = c, c = gc());
	}
	inline void rds(string &s) {
		for (c = gc(); c < 33 || c > 126; c = gc());
		for (s.clear(); c >= 33 && c <= 126; s.pb(c), c = gc());
	}

	template <class I>
	inline void print(I x, char k = '\n') {
		if (!x) pc('0');
		if (x < 0) pc('-'), x = -x;
		while (x) ch[++t] = x % 10 + '0', x /= 10;
		while (t) pc(ch[t--]);
		pc(k);
	}
	template <class I>
	inline void print(I x, I y) {
		print(x, ' '), print(y);
	}
	template <class I>
	inline void print(I x, I y, I z) {
		print(x, ' '), print(y, ' '), print(z);
	}
	template <class I>
	inline void printa(I *a, int n) {
		for (int i = 1; i <= n; i++) print(a[i], " \n"[i==n]);
	}
	inline void printc(char c) {
		pc(c);
	}
	inline void prints(char *s, int n) {
		for (int i = 1; i <= n; i++) pc(s[i]);
		pc('\n');
	}
	inline void prints(string s) {
		int n = s.length();
		while (t < n) pc(s[t++]);
		pc('\n'), t = 0;
	}
	struct Flush {
		~Flush() {
			flush();
		}
	} flusher;
}
using io::rd;
using io::rda;
using io::rdc;
using io::rds;
using io::print;
using io::printa;
using io::printc;
using io::prints;

const int N = 307, inf = 1e9;
int n, k, f[N][N][N];
char s[N];
bool v[N][N][N];

int F(int l, int r, int k) {
	if (k < 0) return -inf;
	if (r - l < 1) return r - l + 1;
	if (v[l][r][k]) return f[l][r][k];
	v[l][r][k] = 1;
	return f[l][r][k] = max(max(F(l + 1, r, k), F(l, r - 1, k)), F(l + 1, r - 1, k - (s[l] != s[r])) + 2);
}

int main() {
	rds(s, n), rd(k), print(F(1, n, k));
	return 0;
}