#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

using Int = long long;

template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }


namespace MCF {
	#define MAXN 1000010
	#define MAXM 1000010
	#define wint int
	#define cint Int
	const wint wEPS = 0;
	const wint wINF = 1001001001;
	const cint cEPS = 0;
	const cint cINF = 1001001001001001001LL;
	int n, m, ptr[MAXN], next[MAXM], zu[MAXM];
	wint capa[MAXM], tof;
	cint cost[MAXM], toc, d[MAXN], pot[MAXN];
	int vis[MAXN], pree[MAXN];
	void init(int _n) {
		n = _n; m = 0; memset(ptr, ~0, n << 2);
	}
	void ae(int u, int v, wint w, cint c) {
		next[m] = ptr[u]; ptr[u] = m; zu[m] = v; capa[m] = w; cost[m] = +c; ++m;
		next[m] = ptr[v]; ptr[v] = m; zu[m] = u; capa[m] = 0; cost[m] = -c; ++m;
	}
	bool solve(int src, int ink, wint flo = wINF) {
		wint f;
		cint c, cc;
		int i, u, v;
		memset(pot, 0, n * sizeof(cint));
	//*
		for (bool cont = 1; cont; ) {
			cont = 0;
			for (u = 0; u < n; ++u) for (i = ptr[u]; ~i; i = next[i]) if (capa[i] > wEPS) {
				if (pot[zu[i]] > pot[u] + cost[i] + cEPS) {
					pot[zu[i]] = pot[u] + cost[i]; cont = 1;
				}
			}
		}
	//*/
		for (toc = 0, tof = 0; tof + wEPS < flo; ) {
			typedef pair<cint,int> node;
			priority_queue< node,vector<node>,greater<node> > q;
			for (u = 0; u < n; ++u) { d[u] = cINF; vis[u] = 0; }
			for (q.push(make_pair(d[src] = 0, src)); !q.empty(); ) {
				c = q.top().first; u = q.top().second; q.pop();
				if (vis[u]++) continue;
				for (i = ptr[u]; ~i; i = next[i]) if (capa[i] > wEPS) {
					cc = c + cost[i] + pot[u] - pot[v = zu[i]];
					if (d[v] > cc) { q.push(make_pair(d[v] = cc, v)); pree[v] = i; }
				}
			}
			if (!vis[ink]) return 0;
			f = flo - tof;
			for (v = ink; v != src; v = zu[i ^ 1]) { i = pree[v]; chmin(f, capa[i]); }
			for (v = ink; v != src; v = zu[i ^ 1]) { i = pree[v]; capa[i] -= f; capa[i ^ 1] += f; }
			tof += f;
			toc += f * (d[ink] - pot[src] + pot[ink]);
			for (u = 0; u < n; ++u) pot[u] += d[u];
		}
		return 1;
	}
}


int N;
char S[2020];
Int V[2020];

int main() {
  for (; ~scanf("%d", &N); ) {
    scanf("%s", S);
    for (int i = 0; i < N; ++i) {
      scanf("%lld", &V[i]);
    }
    
    MCF::init(N * 2 + 2);
vector<int>ids(N);
    for (int i = 0; i < N; ++i) {
      if (S[i] == 'y') {
        MCF::ae(N * 2, i * 2, N, 0);
      }
      if (S[i] == 'i') {
        MCF::ae(i * 2 + 1, N * 2 + 1, N, 0);
      }
ids[i]=MCF::m;
      MCF::ae(i * 2, i * 2 + 1, 1, -V[i]);
      for (int j = i + 1; j < N; ++j) {
        if (S[i] == S[j]) {
          MCF::ae(i * 2, j * 2, N, 0);
          break;
        }
      }
      for (int j = i + 1; j < N; ++j) {
        if ((S[i] == 'y' && S[j] == 'u') || (S[i] == 'u' && S[j] == 'k') || (S[i] == 'k' && S[j] == 'i')) {
          MCF::ae(i * 2 + 1, j * 2, N, 0);
          break;
        }
      }
    }
    
    MCF::ae(N * 2, N * 2 + 1, N, 0);
    MCF::solve(N * 2, N * 2 + 1, N);
    printf("%lld\n", -MCF::toc);
    
vector<int>used(N,0);
for(int i=0;i<N;++i)used[i]=MCF::capa[ids[i]^1];
// cerr<<"used = ";pv(used.begin(),used.end());
Int score=0;
for(int i=0;i<N;++i)if(used[i])score+=V[i];
assert(-MCF::toc==score);
for(int i=0;i<N;++i)if(used[i]){
 int j=i;
 for(char c:{'y','u','k','i'}){
  for(;j<N&&!(S[j]==c&&used[j]);++j){}
  assert(j<N);
  used[j++]=0;
 }
}
for(int i=0;i<N;++i)assert(!used[i]);
  }
  return 0;
}