#include <iostream>
#include <iomanip>
#include <fstream>
#include <string>
#include <array>
#include <vector>
#include <deque>
#include <list>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <stack>
#include <queue>
#include <bitset>
#include <tuple>
#include <cmath>
#include <complex>
#include <algorithm>
#include <utility>
#include <regex>
#include <cstdint>
#include <numeric>
#include <functional>
#include <cassert>

using namespace std;
using ll  = long long;
using ull = unsigned long long;

namespace utils{
#define ALL(x) begin(x), end(x)
#define RALL(x) rbegin(x), rend(x)
    template<class T, class Compare> using p_queue = priority_queue<T, vector<T>, Compare>;
    template<class T> using min_queue = p_queue<T, greater<T>>;
    template<class T> using max_queue = p_queue<T, less<T>>;

    template<class T> inline bool UPMIN(T& X, const T& A){ if(X > A) {X = A; return true;} return false; }
    template<class T> inline bool UPMAX(T& X, const T& A){ if(X < A) {X = A; return true;} return false; }

    template<class T>
    vector<T> VEC(int n, T t){
        return vector<T>(n, t);
    }
    template<class ...Ts>
    auto VEC(int n, Ts ... ts){
        return vector<decltype(VEC(ts...))>(n, VEC(ts...));
    }

    template <class S, class T>
    istream& operator>>(istream& is, tuple<S, T>& t){
        return is >> get<0>(t) >> get<1>(t);
    }

    template <class S, class T, class U>
    istream& operator>>(istream& is, tuple<S, T, U>& t){
        return is >> get<0>(t) >> get<1>(t) >> get<2>(t);
    }

    template <class S, class T>
    ostream& operator<<(ostream& os, const tuple<S, T>& t){
        return os << get<0>(t) << ' ' <<  get<1>(t);
    }

    template <class S, class T, class U>
    ostream& operator<<(ostream& os, const tuple<S, T, U>& t){
        return os << get<0>(t) << ' ' <<  get<1>(t) << ' ' <<  get<2>(t);
    }

    template<class T>
    istream& operator>>(istream& is, vector<T>& v){
        for (auto &&x : v) { is >> x; } return is;
    }

    template<class T>
    ostream& operator<<(ostream& os, const vector<T>& v){
        auto p = v.begin();
        assert(p != v.end());
        os << *p++;
        while(p != v.end()){
            os << ' ' << *p++;
        }
        return os ;
    }

    template<class T>
    ostream& operator<<(ostream& os, const vector<vector<T>>& v){
        auto p = v.begin();
        assert(p != v.end());
        os << *p++;
        while(p != v.end()){
            os << '\n' << *p++;
        }
        return os;
    }

    template<class ...Ts>
    ostream& operator<<(ostream& os, const vector<tuple<Ts...>>& v){
        auto p = v.begin();
        assert(p != v.end());
        os << *p++;
        while(p != v.end()){
            os << '\n' << *p++;
        }
        return os;
    }

    constexpr long long INFLL   = 1'000'000'000'000'000'000ll;
    constexpr int       INF     = 1'000'000'000;
    constexpr double    PI      = 3.14'159'265'358'973;
    constexpr double    EPS     = 1e-10;
}
using namespace utils;


class solver{
    istream& is;
    ostream& os;

public:
    solver(istream& I, ostream& O) :is(I), os(O) {}

    int N, K;
    vector<int> rsp;
    string T;

    bool input() {
        is >> N >> K;
        rsp.resize(3); is >> rsp;
        is >> T;
        return !!is;
    }

    int rsp_int(char t) const{
        if(t == 'r') return 0;
        if(t == 's') return 1;
        else return 2;
    }

    void run();
};

int main(int argc, char *argv[]) {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << setprecision(16) << scientific;
#ifdef XELMH
    string test_cases = "test_D.txt";
    cerr << test_cases << " -->" << endl;
    auto fs = fstream(test_cases, fstream::in);
    int loop = 0;
    while(fs) {
        loop++;
        cout << '#' << loop << "#------\n";
        solver(fs, cout).run();
    }
    if(loop <= 1) {
        cout << "===" << endl;
        while(cin) solver(cin, cout).run();
    }
#else
    solver(cin, cout).run();
#endif
    return 0;
}


void solver::run(){
    if(!input()) return;
    auto dp = VEC(K, 3, 0ll);
    for (int i = 0; i < N; ++i) {
        auto nex = VEC(3, 0ll);
        int te = rsp_int(T[i]);
        te--; if(te < 0) te += 3;
        int n = (te+1)%3;
        int nn = (te+2)%3;

        nex[te] = max(dp[i%K][n], dp[i%K][nn]) + rsp[te];
        nex[n] = max(dp[i%K][te], dp[i%K][nn]);
        nex[nn] = max(dp[i%K][n], dp[i%K][te]);
        dp[i%K] = nex;
    } // end i
    ll ans = 0;
    for (auto &&d : dp) {
        ans += *max_element(ALL(d));
    } // end d
    os << ans << endl;

}


Measured memory_bytes: 5200