using System;
using System.Collections.Generic;
using System.Linq;
using System.IO;
using System.Text;
using static System.Math;
using static System.Array;
using static AtCoder.Tool;
namespace AtCoder
{
    class AC
    {
        const int MOD = 1000000007;
        const int INF = int.MaxValue / 2;
        const long SINF = long.MaxValue / 2;
        const double EPS = 1e-8;
        static readonly int[] dx = { 0, 1, 0, -1 };
        static readonly int[] dy = { 1, 0, -1, 0 };
        //static List<List<int>> G = new List<List<int>>();
        //static List<List<Edge>>G = new List<List<Edge>>();
        //static List<Edge> E = new List<Edge>();

        static void Main(string[] args)
        {
            //var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
            //Console.SetOut(sw);
            var cin = new Scanner();

            var input = cin.ReadSplitInt();
            int N = input[0];
            int K = input[1];
            input = cin.ReadSplitInt();
            int R = input[0];
            int S = input[1];
            int P = input[2];
            string T = Console.ReadLine();
            char[] hd = { 's', 'p', 'r' };
            int[] pt = { R, S, P };

            var h = new List<StringBuilder>();
            for(var i = 0; i < K; i++) { h.Add(new StringBuilder()); }
            for(var i = 0; i < K; i++)
            {
                int itr = i;
                while (itr < T.Length)
                {
                    h[i].Append(T[itr]);
                    itr += K;
                }
            }
            long ans = 0;
            for(var i = 0; i < K; i++)
            {
                int L = h[i].Length;
                var dp = new long[L + 1, 3];
                dp[0, 0] = dp[0, 1] = dp[0, 2] = 0;
                for(var j = 0; j < L; j++)
                {
                    for(var k = 0; k < 3; k++)
                    {
                        int PT = h[i][j] == hd[k] ? pt[k] : 0;
                        dp[j + 1, k] = Max(dp[j, (k + 1) % 3] + PT, dp[j, (k + 2) % 3] + PT);
                    }
                }
                ans += Max(Max(dp[L, 0], dp[L, 1]), dp[L, 2]);
            }
            Console.WriteLine(ans);

            //Console.Out.Flush();
        }
        
        struct Edge
        {
            public int from;

            public int to;
            public long dist;
            public Edge(int t, long c)
            {
                from = -1;
                to = t;
                dist = c;
            }
            public Edge(int f, int t, long c)
            {
                from = f;
                to = t;
                dist = c;
            }

        }
    }
    
    public class Scanner
    {
        public int[] ReadSplitInt()
        {
            return ConvertAll(Console.ReadLine().Split(), int.Parse);
        }
        public long[] ReadSplitLong()
        {
            return ConvertAll(Console.ReadLine().Split(), long.Parse);
        }
        public double[] ReadSplit_Double()
        {
            return ConvertAll(Console.ReadLine().Split(), double.Parse);
        }
    }
    public static class Tool
    {
        static public void Initialize<T>(ref T[] array, T initialvalue)
        {
            for (var i = 0; i < array.Length; i++)
            {
                array[i] = initialvalue;
            }
        }
        static public void Swap<T>(ref T a, ref T b)
        {
            T keep = a;
            a = b;
            b = keep;
        }

        static public void Display<T>(T[,] array2d, int n, int m)
        {
            for (var i = 0; i < n; i++)
            {
                for (var j = 0; j < m; j++)
                {
                    Console.Write($"{array2d[i, j]} ");
                }
                Console.WriteLine();
            }
        }

        static public long LPow(int a, int b)
        {
            return (long)Pow(a, b);
        }
    }
}


Measured memory_bytes: 27208