E

#include <iostream>
#include <vector>
#include <string>
#include <map>
#include <cassert>

using namespace std;


struct Node{

    Node() = default;

    void add_neighbour(char c, int n){
        transitions_.insert({c, n});
    }

    int get_neighbour(char c){
        assert(transitions_.contains(c));
        return transitions_[c];
    }

private:
    map<char, int> transitions_;


};

vector<int> prefix_f(string s){
    auto n = s.size();

    vector<int> pf(n, 0);

    for (int i = 1; i < n; ++i){
        auto j = pf[i-1];
        while (s[j] != s[i]){
            if (j == 0){
                j = -1;
                break;
            }
            j = pf[j-1];
        }
        pf[i] = j+1;
    }

    return pf;
}

class KMP{
public:
    explicit KMP(string& s, vector<char>& alphabet){
        for (int i = 0; i < s.size()+1; ++i){
            Node* new_node = new Node();
            spanning_tree.push_back(new_node);
        }
        if (s.empty()){
            return;
        }
        auto m = s.size();

        prefix_v = prefix_f(s);

        for (int q = 0; q < m+1; ++q){
            for (char c : alphabet){
                if (q > 0 && c != s[q]){
                    auto address = get_transition(prefix_v[q-1], c);
                    add_transition(q, c, address);
                }
                else {
                    add_transition(q, c, q + (c == s[q]));
                }
            }
        }

    }

    vector<Node*> spanning_tree;
    vector<int> prefix_v;


    void add_transition(int n, char a, int direction){
        assert(n<=spanning_tree.size());

        spanning_tree[n]->add_neighbour(a, direction);
    }

    int get_transition(int n, char c){
        return spanning_tree[n]->get_neighbour(c);
    }
};


int main(){
    int o;
    cin >> o;

    int alphabet_size;
    cin >> alphabet_size;

    int interruptions;
    cin >> interruptions;

    string s;
    cin >> s;

    vector<char> alphabet;

    char last = 'a';

    for (int i = 0; i < alphabet_size; ++i){
        alphabet.push_back(last);
        ++last;
    }

    KMP kmp = KMP(s, alphabet);

    int64_t result = s.size();

    // TODO: length of the rest of string with max from alphabet interuption
    // (string length before interruption) + (string length between interuptions)*interruptions + (length of string after interruption)

    int last_change = 0;

    for (int i = 1; i < s.size(); ++i){ //iterating over fav word
        // finding max (string length between interuptions)
        int64_t between = 0;
        int64_t before = 0;
        int64_t after = 0;

        for (auto c : alphabet){
            auto r = kmp.spanning_tree[i]->get_neighbour(c);
            between = i - r;
            before = r;
            after = s.size() - i;

            if (before + between*(interruptions+1) + after > result){
                result = before + between*(interruptions+1) + after;
                last_change = i;
            }
        }
    }

    cout << result;

    return 0;
}