#include<iostream>
#include<cstdio>
#include<algorithm>
#include<vector>
using namespace std;
using ll=long long;
string s,t;
int len,n;
ll ans=0;
void calc(){
    ll now=0;
    for(int i=0;i<n;i++){
        int j=0;
        for(;j<len&&j+i<n;j++){
            if(s[j]!=t[i+j]){
                break;
            }
        }
        now+=min(j,min(len,n-i));
    }
    ans=max(ans,now);
} 
vector<char>cs;
bool vis[30];
void dfs(int x){
    if(x==n){
        calc();
        return;
    }
    for(char c:cs){
        t.push_back(c);
        dfs(x+1);
        t.pop_back();
    }
}
int main(){
    freopen("string.in","r",stdin);
    freopen("string.out","w",stdout);
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    cin>>s>>n;
    len=s.size();
    for(int i=0;i<len;i++){
        if(!vis[s[i]-'a']){
            cs.push_back(s[i]);
            vis[s[i]-'a']=1;
        }
    }
    dfs(0);
    cout<<ans;
    return 0;
}