#include<iostream>
#include<algorithm>
#include<bits/stdc++.h>
using namespace std;
/*---------------------DEBUGGING--------------------------------------------*/
void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifndef ONLINE_JUDGE
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif
/*-------------------------------------------------------------------------------------*/
#define mp make_pair
#define pb push_back
#define ll long long
#define pii pair<int,int>
#define pcc pair<char,char>
#define F first
#define S second
#define int long long
#define pi 3.141592653589793238462643383279502
#define M  1000000007
#define rep(i,a,n) for(int i=a;i<n;i++)
#define N 300005
#define vi vector<int>
#define all(v) v.begin(),v.end()


signed main()
{
   ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
   int n,k;
   cin>>n>>k;
   int r,s,p;
   cin>>r>>s>>p;
   string st;
   cin>>st;
   string ans="";
   vector<int>v;
   for(int i=0;i<st.length();i++)
   {
       if(i<k)
       {
           if(st[i]=='r')ans+='p';
           if(st[i]=='s')ans+='r';
           if(st[i]=='p')ans+='s';
       }
       else
       {
           if(st[i]=='r')
           {
               if(ans[i-k]!='p')ans+='p';
               else
               {
                   if((i+k)<st.length())
                   {
                       if(st[i+k]=='s')ans+='s';
                       if(st[i+k]=='r')ans+='r';
                       if(st[i+k]=='p')ans+='p';
                       v.pb(i);
                   }
               }
           }

           if(st[i]=='p')
           {
               if(ans[i-k]!='s')ans+='s';
               else
               {
                   if((i+k)<st.length())
                   {

                       if(st[i+k]=='s')ans+='s';
                       if(st[i+k]=='r')ans+='r';
                       if(st[i+k]=='p')ans+='p';
                       v.pb(i);
                   }
               }
           }
           if(st[i]=='s')
           {
               if(ans[i-k]!='r')ans+='r';
               else
               {
                   if((i+k)<st.length())
                   {

                       if(st[i+k]=='s')ans+='s';
                       if(st[i+k]=='r')ans+='r';
                       if(st[i+k]=='p')ans+='p';
                       v.pb(i);
                   }
               }
           }

       }
   }
   int sum=0;
   int j=0;
   for(int i=0;i<ans.length();i++)
   {   if(j<v.size()){if(i==v[j]){j++;continue;}}
       if(ans[i]=='r')sum+=r;
       if(ans[i]=='s')sum+=s;
       if(ans[i]=='p')sum+=p;

   }
   cout<<sum<<endl;
}


Measured memory_bytes: 1148