#include<bits/stdc++.h> using namespace std; int main() { int n,k,r,s,t; char a[25]; string t; cin>>n>>k>>r>>s>>t; for(int i=0;i<n;i++){ cin>>a[i]; } for(int i=1;i<=n;i++){ if(a[i]==a[i-k]){ continue; } else if(a[i]='r') sum+=c; else if(a[i]=='s') sum+=r; else if(a[i]=='c')sum+=s; } cout<<sum; return 0; }