#include <bits/stdc++.h>
using namespace std;

#define pb push_back
#define eb emplace_back
#define mp make_pair
#define mt make_tuple
#define ms(arr, val) memset(arr, val, sizeof(arr))

#define N 100000
#define R 51
#define INF (int)100000

int n, k, g1, g2, g3, s; string str;
int dp[R];

int f(int i, int j)
{
    if(i >= n && j == 0)
    {
        return 0;
    }
    else if(i >= n && j != 0)
    {
        return -INF;
    }
    else if(i + 2 < n && str[i] == '.' && str[i + 1] == '#' && str[i + 2] == '.')
    {
        return max(f(i + 3, j - 1), f(i + 2, j));
    }
    else if(i + 1 < n && str[i] == '.' && str[i + 1] == '.')
    {
        return max(1 + f(i + 2, j), f(i + 1, j));
    }
    else
    {
        return f(i + 1, j);
    }
}

int main()
{
    if(fopen("input_muntu.in", "r"))
    {
        freopen("input_muntu.in", "r", stdin);
        freopen("output_muntu.out", "w", stdout);
    }

    ms(dp, 0); s = 0;
    cin >> n >> k >> g1 >> g2 >> g3 >> str;
    for(char ch : str) if(ch == '.') s++;

    long long ans = 0, t1, t2, t3;
    for(int i = 0; i < R; i++)
    {
        dp[i] = f(0, i);
        if(dp[i] * g2 + i * g3 > ans)
        {
            ans = dp[i] * g2 + i * g3;
            t2 = dp[i]; t3 = i;
        }
    }

    t1 = s - (t2 + t3) * 2;
    k = k - t1;

    if(k < 0)
    {
        t1 = t1 + k;
        k = 0;
    }

    if(g2 > g3)
    {
        swap(g2, g3);
        swap(t2, t3);
    }

    while(k > 0)
    {
        if(g1 > g2 && t2 > 0)
        {
            t1 = t1 + 2;
            t2 = t2 - 1;

            if(k > 1) k--;
            else t1--;
        }
        else if(g1 > g3 && t3 > 0)
        {
            t1 = t1 + 2;
            t3 = t3 - 1;

            if(k > 1) k--;
            else t1--;
        }
        else if(g1 * 2 > g2 && t2 > 0 && k > 1)
        {
            t1 = t1 + 2;
            t2 = t2 - 1;
            k--;
        }
        else if(g1 * 2 > g3 && t3 > 0 && k > 1)
        {
            t1 = t1 + 2;
            t3 = t3 - 1;
            k--;
        }
        k--;
    }

    ans = t1 * g1 + t2 * g2 + t3 * g3;
    cout << ans << endl;

    return 0;
}