#include <bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
 
#define IOS ios :: sync_with_stdio(false); cin.tie(0); cout.tie(0)
#define AfterDecimal(n) cout << fixed << setprecision(n);
#define pb push_back
#define pp(a, b) pair <a, b>
#define ll long long int
#define ld long double
#define all(a) a.begin(), a.end()
#define pi pair<int, int>
#define pll pair<ll, ll>
#define F first
#define S second
#define itr iterator
#define bits(x) __builtin_popcount(x)
#define fori(n)  for (ll i = 0; i < n; i++)
#define forj(n)  for (ll j = 0; j < n; j++)
#define fork(n)  for (ll k = 0; k < n; k++)
#define vll vector <ll>
#define mll map <ll, ll>
#define vpll vector <pll>
 
 
using namespace __gnu_pbds;
using namespace std;
 
template <class T> T printr(T p){ cout << p << '\n'; return 0; }
template <class T> T printe(T p){ cout << p << '\n'; exit(0); }
template <class T> bool uin(T &a, T b) { return a > b ? (a = b, true) : false; }
template <class T> bool uax(T &a, T b) { return a < b ? (a = b, true) : false; }
 
 
template <typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
 
#ifdef LOCAL
#define debug(...) __f(#__VA_ARGS__, __VA_ARGS__)
template<typename Arg1>
void __f(const char* name, Arg1&& arg1){
    cout << "# "<< name << " = " << arg1 << '\n';
}
template<typename Arg1, typename... Args>
void __f(const char* names, Arg1 && arg1, Args &&... args){
        const char* comma = strchr(names + 1 ,',');
        cout << "# ";
        cout.write(names, comma - names)<< " = " << arg1 << " | ";
        __f(comma + 1, args...);
}
#else
#define debug(...) 36
#endif
 
ll power(ll x, ll y, ll p){ 
   ll res = 1;
   x = x % p;  
   while (y > 0) {
      if (y & 1) 
         res = (res * x) % p; 
      y = y >> 1;
      x = (x * x) % p; 
   }
   return res;
}
 
const ll INF = (ll)(8e18);
const ll MOD = 1e9 + 7;
 
const int maxn = 100010;

int dp[maxn][3][2];

int32_t main(){
    IOS;
    #ifndef ONLINE_JUDGE
    // freopen("input.txt", "r", stdin);
    // freopen("output.txt", "w", stdout);
    #endif
    int n,k; cin >> n >> k;
    int r,s,p; cin >> r >> s >> p;
    string t; cin >> t;
    if(t[0] == 'r'){
        dp[1][1][1] += p;
    }else if(t[0] == 'p'){
        dp[1][2][1] += s;
    }else{
        dp[1][0][1] += r;
    }
    for(int i = 2; i <= n; i++){
        if(i <= k){
            if(t[i - 1] == 'r'){
                dp[i][1][1] += p;
            }else if(t[i - 1] == 'p'){
                dp[i][2][1] += s;
            }else{
                dp[i][0][1] += r;
            }
        }else{
            if(t[i - 1] == 'r'){
                dp[i][1][0] = max(dp[i - k][1][1], dp[i - k][1][0]);
                dp[i][1][0] = max(dp[i][1][0], max(dp[i - k][2][0], dp[i - k][2][1]));
                dp[i][1][0] = max(dp[i][1][0], max(dp[i - k][0][0], dp[i - k][0][1]));
                if(t[i - k - 1] == 'r'){
                    dp[i][1][1] = dp[i - k][1][0] + p;
                }else{
                    dp[i][1][1] = dp[i][1][0] + p;
                }
            }else if(t[i - 1] == 'p'){
                dp[i][2][0] = max(dp[i - k][2][1], dp[i - k][2][0]);
                dp[i][2][0] = max(dp[i][2][0], max(dp[i - k][1][0], dp[i - k][1][1]));
                dp[i][2][0] = max(dp[i][2][0], max(dp[i - k][0][0], dp[i - k][0][1]));
                if(t[i - k - 1] == 'p'){
                    dp[i][2][1] = dp[i - k][2][0] + s;
                }else{
                    dp[i][2][1] = dp[i][2][0] + s;
                }
            }else{
                dp[i][0][0] = max(dp[i - k][0][1], dp[i - k][0][0]);
                dp[i][0][0] = max(dp[i][0][0], max(dp[i - k][1][0], dp[i - k][1][1]));
                dp[i][0][0] = max(dp[i][0][0], max(dp[i - k][2][0], dp[i - k][2][1]));
                if(t[i - k - 1] == 's'){
                    dp[i][0][1] = dp[i - k][0][0] + r;
                }else{
                    dp[i][0][1] = dp[i][0][0] + r;
                }
            }
        }
    }
    int ans = 0;
    for(int i = n; i >= (n - k + 1); i--){
         int ar = max(dp[i][0][0], dp[i][0][1]);
         ar = max(ar, max(dp[i][1][0], dp[i][1][1]));
         ar = max(ar, max(dp[i][2][0], dp[i][2][1]));
         ans += ar;
    }
    cout << ans << '\n';
    #ifdef LOCAL
    cerr << "Time elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << " s.\n";
    #endif
}

Measured memory_bytes: 2768