/*
 
Author: Haze
 
2024/3/24
 
*/
 
#include <bits/stdc++.h>
 
#define irep(i, l, r) for(int i = (l); i <= (r); ++ i)
#define drep(i, r, l) for(int i = (r); i >= (l); -- i)
#define IOS ios::sync_with_stdio(false), cin.tie(nullptr);
using namespace std;
typedef long long ll;
 
inline ll read() {
    ll s = 0;
    bool fl = false;
    char ch = (char) getchar();
    while (!isdigit(ch)) {
        if (ch == '-')fl = true;
        ch = (char) getchar();
    }
    while (isdigit(ch)) {
        s = s * 10 + (ch ^ 48);
        ch = (char) getchar();
    }
    return fl ? -s : s;
}
 
const int mod = 1000000000 + 7;
const int itinf = 1000000999;
const ll llinf = 2e18;
const int N = 300099;
int n, k;
int tot = 1;
int nxt[N][26];
ll sz[N], f[N], res[N];
//string STA;
 
void dfs(int x){
    vector<int>fr;
    fr.reserve(26);
    for(int i = 0; i < 26; ++ i){
        if(nxt[x][i]){
//            STA.push_back((char)('a' + i));
            dfs(nxt[x][i]);
//            STA.pop_back();
            fr.emplace_back(res[nxt[x][i]]);
            f[x] += f[nxt[x][i]];
        }
    }
    sort(fr.begin(), fr.end());
    int cur = sz[x];
//    cerr << STA << endl;
    for(int num : fr){
//        cerr << num << ' ';
        if(cur + num <= k)cur += num;
        else f[x] ++;
    }
//    cerr << endl;
    res[x] = cur;
}
 
void solve() {
    n = read(), k = read();
    irep(i, 1, n){
        string s;
        cin >> s;
        int x = 1;
        for(char c : s){
            if(! nxt[x][c - 'a']){
                nxt[x][c - 'a'] = ++ tot;
            }
            x = nxt[x][c - 'a'];
        }
        sz[x] ++;
    }
    dfs(1);
    cout << f[1] + (res[1] > 0);
}
 
int main() {
    // IOS
    int T = 1;
    while (T--) {
        solve();
    }
    return 0;
}

answer.code:8:1: error: extended character   is not valid in an identifier
    8 |  
      | ^
answer.code:10:1: error: extended character   is not valid in an identifier
   10 |  
      | ^
answer.code:16:1: error: extended character   is not valid in an identifier
   16 |  
      | ^
answer.code:31:1: error: extended character   is not valid in an identifier
   31 |  
      | ^
answer.code:41:1: error: extended character   is not valid in an identifier
   41 |  
      | ^
answer.code:65:1: error: extended character   is not valid in an identifier
   65 |  
      | ^
answer.code:83:1: error: extended character   is not valid in an identifier
   83 |  
      | ^
answer.code:8:1: error: ‘ ’ does not name a type
    8 |  
      | ^
In file included from /usr/include/c++/13/bits/stl_algobase.h:62,
                 from /usr/include/c++/13/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/13/bits/stdc++.h:51,
                 from answer.code:9:
/usr/include/c++/13/ext/type_traits.h:164:35: error: ‘constexpr const bool __gnu_cxx::__is_null_pointer’ redeclared as different kind of entity
  164 |   __is_null_pointer(std::nullptr_t)
      |                                   ^
/usr/include/c++/13/ext/type_traits.h:159:5: note: previous declaration ‘template<class _Type> constexpr bool __gnu_cxx::__is_null_pointer(_Type)’
  159 |     __is_null_pointer(_Type)
      |     ^~~~~~~~~~~~~~~~~
/usr/include/c++/13/ext/type_traits.h:164:26: error: ‘nullptr_t’ is not a member of ‘std’; did you mean ‘nullptr_t’?
  164 |   __is_null_pointer(std::nullptr_t)
      |                          ^~~~~~~~~
In file included from /usr/include/c++/13/cstddef:50,
                 from /usr/include/x86_64-linux-gnu/c++/13/bits/stdc++.h:41:
/usr/lib/gcc/x86_64-linux-gnu/13/include/stddef.h:443:29: note: ‘nullptr_t’ declared here
  443 |   typedef decltype(nullptr) nullptr_t;
      |                             ^~~~~~~~~
In file included from /usr/include/c++/13/bits/stl_pair.h:60,
                 from /usr/include/c++/13/bits/stl_algobase.h:64:
/usr/include/c++/13/type_traits:510:26: error: ‘std::size_t’ has not been declared
  510 |   template<typename _Tp, std::size_t _Size>
      |                          ^~~
/usr/include/c++/13/type_traits:511:25: error: ‘_Size’ was not declared in this scope
  511 |     struct is_array<_Tp[_Size]>
      |                         ^~~~~
/usr/include/c++/13/type_traits:511:31: error: template argument 1 is invalid
  511 |     struct is_array<_Tp[_Size]>
      |                               ^
/usr/include/c++/13/type_traits:617:33: error: ‘nullptr_t’ is not a member of ‘std’; did you mean ‘nullptr_t’?
  617 |     struct is_null_pointer<std::nullptr_t>
      |                                 ^~~~~~~~~
/usr/lib/gcc/x86_64-linux-gnu/13/include/stddef.h:443:29: note: ‘nullptr_t’ declared here
  443 |   typedef decltype(nullptr) nullptr_t;
      |                             ^~~~~~~~~
/usr/include/c++/13/type_traits:617:42: error: template argument 1 is invalid
  617 |     struct is_null_pointer<std::nullptr_t>
      |                                          ^
/usr/include/c++/13/type_traits:621:48: error: template argument 1 is invalid
  621 |     struct is_null_pointer<const std::nullptr_t>
      |                                                ^
/usr/include/c++/13/type_traits:625:51: error: template argument 1 is invalid
  625 |     struct is_null_pointer<volatile std::nullptr_t>
      |                                                   ^
/usr/include/c++/13/type_traits:629:57: error: template argument 1 is invalid
  629 |     struct is_null_pointer<const volatile std::nullptr_t>
      |                                                         ^
/usr/include/c++/13/type_traits:1348:37: error: ‘size_t’ is not a member of ‘std’; did you mean ‘size_t’?
 1348 |     : public integral_constant<std::size_t, alignof(_Tp)>
      |                                     ^~~~~~
/usr/lib/gcc/x86_64-linux-gnu/13/include/stddef.h:214:23: note: ‘size_t’ declared here
  214 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
/usr/include/c++/13/type_traits:1348:57: error: template argument 1 is invalid
 1348 |     : public integral_constant<std::size_t, alignof(_Tp)>
      |                                                         ^
/usr/include/c++/13/type_traits:1357:37: error: ‘size_t’ is not a member of ‘std’; did you mean ‘size_t’?
 1357 |     : public integral_constant<std::size_t, 0> { };
      |                                     ^~~~~~
/usr/lib/gcc/x86_64-linux-gnu/13/include/stddef.h:214:23: note: ‘size_t’ declared here
  214 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
/usr/include/c++/13/type_traits:1357:46: error: template argument 1 is invalid
 1357 |     : public integral_constant<std::size_t, 0> { };
      |                                              ^
/usr/include/c++/13/type_traits:1359:26: error: ‘std::size_t’ has not been declared
 1359 |   ...