#include <bits/stdc++.h>
using namespace std;
#define REP(i,x,n) for(int i=x;i<(int)n;i++)
#define rep(i,n) REP(i,0,n)
#define sp(p) cout<<setprecision(16)<<fixed<<p<<endl;
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define SORT(a) sort(all(a))
#define RSORT(a) sort(rall(a))
#define UNIQ(a) unique(all(a))
#define UNIQNUM(a) UNIQ(a)-a.begin()
#define UNIQIT(a) a.erase(UNIQ(a), a.end());
#define VOUT(v,i) cout<<#v<<": ";for(int i=0;i<(int)v.size();i++){cout<<v[i]<<" ";}cout<<"\n";
#define vout(v) VOUT(v,z);
#define vmin(v) *min_element(all(v))
#define vmax(v) *max_element(all(v))
#define vsum(v) accumulate(all(v), 0LL);
#define MOUT(m,r,c) rep(i,r){rep(j,c){cout<<m[i][j]<<" ";}cout<<endl;}
#define mout(m) MOUT(m,m.size(),m[0].size())
#define debg(a) cout<<#a<<": "<<a<<endl;
#define show(a) for(cont &y:a){for(cont &x:y){cout<<x<<" ";}cout<<endl;}
#define digit(a) to_string(a).length();
template<class T>inline int out(const T &t){ print(t); putchar('\n'); return 0; }
template<class T>inline T gcd(T a,T b){if(b==0)return a; return(gcd(b,a%b));}
template<class T>inline T lcm(T a,T b){return a/gcd(a,b)*b;}
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> P;
typedef vector<ll> V;
// const long long MOD=1000000007;
const long long INF = 1e18;
#define EPS (1e-7)
#define PI (acos(-1))
template<class T>
inline bool chmax(T &a, T b) {
    if(a < b) { a = b; return true; }
    return false;
}
template<class T>
inline bool chmin(T &a, T b) {
    if(a > b) { a = b; return true; }
    return false;
}


void solve(long long N, long long K, long long R, long long S, long long P, std::string T){
    ll score = 0;
    string myhand;
    for (ll i = 0; i < N; i++) {
        if(T[i]=='r'){
            // if((i-K)>=0 && T[i-K]=='r'){
            if((i-K)>=0 && myhand[i-K]=='p'){
                score+=0;
                if((i+K)<N && T[i+K]=='s'){
                    myhand+='s';
                }else{
                    myhand+='r';
                }
            }else{
                score+=P;
                myhand+='p';
            }
        }else if(T[i]=='s'){
            // if((i-K)>=0 && T[i-K]=='s'){
            if((i-K)>=0 && myhand[i-K]=='r'){
                score+=0;
                if((i+K)<N && T[i+K]=='p'){
                    myhand+='p';
                }else{
                    myhand+='s';
                }
            }else{
                score+=R;
                myhand+='r';
            }
        }else{
            // if((i-K)>=0 && T[i-K]=='p'){
            if((i-K)>=0 && myhand[i-K]=='s'){
                score+=0;
                if((i+K)<N && T[i+K]=='r'){
                    myhand+='r';
                }else{
                    myhand+='p';
                }
            }else{
                score+=S;
                myhand+='s';
            }
        }
    }
    cout << score << "\n";
}

int main(){
    long long N;
    scanf("%lld",&N);
    long long K;
    scanf("%lld",&K);
    long long R;
    scanf("%lld",&R);
    long long S;
    scanf("%lld",&S);
    long long P;
    scanf("%lld",&P);
    std::string T;
    std::cin >> T;
    solve(N, K, R, S, P, T);
    return 0;
}


Measured memory_bytes: 640