/*
* C++11 code template for contests.
* @author: Andrei Kalendarov
* @e-mail: andreykalendarov@gmail.com
*/

//#define ANDREIKKAA_ALLOCATOR
const int _ML = 250;

const char _inpf[] =
#if defined(ANDREIKKAA)
        "input.txt"
#else
""
#endif
;
const char _outf[] =
#if defined(ANDREIKKAA)
        ""
#else
""
#endif
;

#if defined(ANDREIKKAA)
#undef NDEBUG
#else
#pragma GCC optimize("O3,no-stack-protector")
#endif
#include <bits/stdc++.h>
#if !defined(ANDREIKKAA)
#define endl '\n'
#endif
#define x first
#define y second
using namespace std;
#define rand abcdefghijklmnopqrstuvwxyz
#define random_shuffle abcdefghijklmnopqrstuvwxyz
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
typedef long long ll;
typedef long double ld;
const ld PI = 3.14159265358979323846;
mt19937 rd(228);
#if defined(ANDREIKKAA_ALLOCATOR)
char _mem[_ML * 1024 * 1024];
size_t _ptr = 0;
inline void* operator new (size_t _x) { _ptr += _x; assert(_ptr < _ML * 1024 * 1024); return _mem + _ptr - _x; }
inline void operator delete (void*) { }
#endif
template<typename T, typename U> inline ostream &operator<< (ostream &_out, const pair<T, U> &_p) { _out << _p.first << ' ' << _p.second; return _out; }
template<typename T, typename U> inline istream &operator>> (istream &_in, pair<T, U> &_p) { _in >> _p.first >> _p.second; return _in; }
template<typename T> inline ostream &operator<< (ostream &_out, const vector<T> &_v) { if (_v.empty()) { return _out; } _out << _v.front(); for (auto _it = ++_v.begin(); _it != _v.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T> inline istream &operator>> (istream &_in, vector<T> &_v) { for (auto &_i : _v) { _in >> _i; } return _in; }
template<typename T> inline ostream &operator<< (ostream &_out, const set<T> &_s) { if (_s.empty()) { return _out; } _out << *_s.begin(); for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T> inline ostream &operator<< (ostream &_out, const multiset<T> &_s) { if (_s.empty()) { return _out; } _out << *_s.begin(); for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T> inline ostream &operator<< (ostream &_out, const unordered_set<T> &_s) { if (_s.empty()) { return _out; } _out << *_s.begin(); for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T> inline ostream &operator<< (ostream &_out, const unordered_multiset<T> &_s) { if (_s.empty()) { return _out; } _out << *_s.begin(); for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T, typename U> inline ostream &operator<< (ostream &_out, const map<T, U> &_m) { if (_m.empty()) { return _out; } _out << '(' << _m.begin()->first << ": " << _m.begin()->second << ')'; for (auto _it = ++_m.begin(); _it != _m.end(); ++_it) { _out << ", (" << _it->first << ": " << _it->second << ')'; } return _out; }
template<typename T, typename U> inline ostream &operator<< (ostream &_out, const unordered_map<T, U> &_m) { if (_m.empty()) { return _out; } _out << '(' << _m.begin()->first << ": " << _m.begin()->second << ')'; for (auto _it = ++_m.begin(); _it != _m.end(); ++_it) { _out << ", (" << _it->first << ": " << _it->second << ')'; } return _out; }

/* ________ CODE ________ */

const int N = 302;
int dp[N][N][N];

inline void _main_function()
{
    string s;
    cin >> s;
    int n = sz(s);

    for(int i = 0; i < n; ++i)
    {
        dp[i][i][0] = 1;
    }

    int k;
    cin >> k;

    for(int len = 2; len <= n; ++len)
    {
        for(int l = 0; l + len <= n; ++l)
        {
            int r = l + len - 1;
            int to = min(k, (len + 1) / 2);
            for(int i = 0; i <= to; ++i)
            {
                dp[l][r][i] = max(dp[l + 1][r][i], dp[l][r - 1][i]);
                if(s[l] == s[r])
                {
                    dp[l][r][i] = max(dp[l][r][i], dp[l + 1][r - 1][i] + 2);
                }
                else if(i > 0)
                {
                    dp[l][r][i] = max(dp[l][r][i], dp[l + 1][r - 1][i - 1] + 2);
                }
            }
        }
    }

    int ans = 0;
    for(int i = 0; i <= k; ++i)
    {
        ans = max(ans, dp[0][n - 1][i]);
    }
    cout << ans << endl;
}

/* ________ CODE ________ */

int main()
{
#if defined(ANDREIKKAA)
    time_t _start = clock();
#endif
    if (_inpf[0] != '\0') assert(freopen(_inpf, "r", stdin) != nullptr);
    if (_outf[0] != '\0') assert(freopen(_outf, "w", stdout) != nullptr);
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);

    cout << setprecision(20);
    cout << fixed;

    _main_function();
#if defined(ANDREIKKAA)
    cout << "Time: " << (clock() - _start) / (ld)CLOCKS_PER_SEC << endl;
#endif
}


Measured memory_bytes: 106752