#define __mode_debug__
/*   ξ
     ll
   ＿ll＿
 ／  ∞  ＼
│*  Ａ  *│
│*  Ｃ  *│
│*  祈  *│
│*  願  *│
│*      *│
 ￣￣￣￣￣    */
//C++14 (GCC 5.4.1)
#include <bits/stdc++.h>
using namespace std;
#ifdef __mode_debug__
    #define DBG
#else
    #define DBG if(false)
#endif

#define LLINF (1LL<<60)
typedef long long ll;
#define mod 1000000007

#define repd(i,a,b) for (int i=(a);i<(b);i++)
#define rep(i,n) repd(i,0,n)
#define rrepd(i,a,b) for(int i=(a);i>=(b);i--)
#define repi(itr,ds) for(auto itr=ds.begin();itr!=ds.end();itr++)

template<typename T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<typename T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

template < typename T > inline string toString( const T &a ) { ostringstream oss; oss << a; return oss.str(); }

//DUMP
//  ostream vector<T> , vector<vector<T>> , set<T> ,queue<T> , priority_queue<T> , pair<T,U> , map<T,U>
template<class T> ostream& operator<<(ostream&os,vector<T>&vec){os<<"{ ";rep(i,vec.size()) os<<((i==0)?"":", ")<<i<<":"<<vec[i];os<<" }";return os;}
template<class T> ostream& operator<<(ostream&os,vector<vector<T>>&vec){os<<"{"<<endl;rep(i,vec.size())os<<"\t   "<<i<<":"<<vec[i]<<((i==vec.size()-1)? "":",")<<endl;os<<"\t }";return os;}
template<class T> ostream& operator<<(ostream&os,set<T>&p){os<<"{ ";repi(itr,p)  os<<((itr==p.begin())?"":", ")<<*itr;os<<" }";return os;}
template<class T> ostream& operator<<(ostream&os,queue<T>&p){queue<T> q(p);os<<"[< "<<(q.empty()?" <]":"");while(!q.empty()){os<<q.front();q.pop();os<< (q.empty() ? " <]" : ", ");}return os;}
template<class T> ostream& operator<<(ostream&os,priority_queue<T>&p){priority_queue<T> q(p);os<<"[< "<<(q.empty()?" <]":"");while(!q.empty()){os<<q.top();q.pop();os<< (q.empty() ? " <]" : ", ");}return os;}
template<class T,class U> ostream& operator<<(ostream&os,pair<T,U>&p){os<<"("<<p.first<<","<<p.second<<")";return os;}
template<class T,class U> ostream& operator<<(ostream&os,map<T,U>&p){os<<"{ ";repi(itr,p)os<<((itr==p.begin())?"":", ")<<itr->first<<":"<<itr->second;os<<" }";return os;}
void dump_f(string &nm){cerr<<endl;}
template<class T,class... Ts> void dump_f(string &nm,T &&x,Ts&&... ts){int l=nm.find_first_of(',');string name(nm,0,l),nx(nm,l+1,-1);cerr<<"  "<<name<<"\t:"<<x<<endl;dump_f(nx,forward<Ts>(ts)...);}
template<class... Ts> void dump_m(int &&ln,string &&nm,Ts&&... ts){cerr<<"[ln:"<<ln<<"]"<<endl;dump_f(nm,forward<Ts>(ts)...);}
#define dump(...) DBG dump_m(__LINE__,#__VA_ARGS__,__VA_ARGS__)

#define lower_bound_idx(V,c) distance(V.begin(),lower_bound(V.begin(),V.end(),c))


int main() {
    ios::sync_with_stdio(false);//stdoutとcoutの同期解除
    cin.tie(nullptr);//cinとcoutの同期解除
    
    int N,K,R,S,P;
    string T;
    cin >>N>>K;
    cin >>R>>S>>P;
    cin >>T;

    //-----------------------------------
    bool is=false;
    int ans=0;

    vector<int> dpr(K,0),dps(K,0),dpp(K,0);

    switch(T[0]){
        case 'r':dpp[0]=P;break;
        case 's':dpr[0]=R;break;
        case 'p':dps[0]=S;break;
    }
    int tr,ts,tp;
    repd(i,1,N){
        if(i/K>0){
            tr=dpr[i%K]; ts=dps[i%K]; tp=dpp[i%K];
        }else{
            tr=0;ts=0;tp=0;
        }
        dpr[i%K]=max(ts,tp);
        dps[i%K]=max(tr,tp);
        dpp[i%K]=max(tr,ts);
        switch(T[i]){
            case 'r':dpp[i%K]+=P;break;
            case 's':dpr[i%K]+=R;break;
            case 'p':dps[i%K]+=S;break;
        }
    }
    rep(i,K){
        ans+=max({dpr[i],dps[i],dpp[i]});
    }
    cout << ans <<endl;
    return (0);
}

Measured memory_bytes: 1488