/*input
30 5
325 234 123
rspsspspsrpspsppprpsprpssprpsr
*/
/**
    Author: Kristopher Paul
    Date Created: 29-12-2019
    Contest Name:
                _/    _/   _/_/_/_/   _/   _/_/_/_/
               _/  _/     _/    _/   _/   _/
              _/_/       _/_/_/_/   _/   _/_/_/_/
             _/  _/     _/  _/     _/         _/
            _/    _/   _/    _/   _/   _/_/_/_/
**/
#include<bits/stdc++.h>
#include<stdio.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define int ll
#define pb push_back
#define INF 1e18
#define MOD 1000000007
//#define MOD 998244353
#define mp make_pair
const double PI=3.141592653589793238462643383279502884197169399375105820974944;
#define REP(i,n) for (int i = 0; i < n; i++)
#define FOR(i,a,b) for (int i = a; i < b; i++)
#define REPD(i,n) for (int i = n-1; i >= 0; i--)
#define FORD(i,a,b) for (int i = a; i >= b; i--)
#define remax(a,b) a = max(a,b)
#define remin(a,b) a = min(a,b)
#define umap unordered_map
#define pii pair<int,int>
#define F first
#define S second
#define mii map<int,int>
#define vi vector<int>
#define vvi vector<vi>
#define itr :: iterator it
#define all(v) v.begin(),v.end()
#define WL(t) while(t--)
#define gcd(a,b) __gcd((a),(b))
#define lcm(a,b) ((a)*(b))/gcd((a),(b))
#define out(x) cout << #x << " is " << x << endl
#define FastIO ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);

//Uncomment for File I/O
/*
#define cin fin
#define cout fout

ifstream fin("cowmbat.in");
ofstream fout("cowmbat.out");
*/

using namespace std;
//using namespace __gnu_pbds;

//typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> pbds; // set
//typedef tree<int,null_type,less_equal<int>,rb_tree_tag,tree_order_statistics_node_update> pbds; // multiset

int ModExp(int x,int y,int m){
    int res = 1;
    x = x % m;
    while (y > 0)
    {
        if (y & 1)
            res = (res*x) % m;

        y = y>>1;
        x = (x*x) % m;
    }
    return res;
}

void solve(){
    int n,k;
    cin >> n >> k;
    int r,s,p;
    cin >> r >> s >> p;
    string m;
    cin >> m;
    string t = "";
    int ans = 0;
    FOR(i,0,n){
        if(m[i] == 's'){
            t += 'r';
            ans += r;
        }else if(m[i] == 'r'){
            t += 'p';
            ans += p;
        }else{
            t += 's';
            ans += s;
        }
    }
    FOR(i,0,k){
        for(int j = i+k;j < n;j += k){
            if(t[j] == t[j-k]){
                umap<char,bool> d;
                d[t[j-k]] = true;
                if(t[j] == 's'){
                    ans -= s;
                }else if(t[j] == 'r'){
                    ans -= r;
                }else{
                    ans -= p;
                }
                if((j+k) < n){
                    d[t[j+k]] = true;
                }
                if(d['s'] == false){
                    t[j] = 's';
                }else if(d['r'] == false){
                    t[j] = 'r';
                }else{
                    t[j] = 'p';
                }
            }
        }
    }
    cout << ans << endl;
}

signed main(){
    FastIO;
    int t = 1;
//    cin >> t;
    WL(t){
        solve();
    }
}


Measured memory_bytes: 640