#include #include using namespace std; typedef unsigned long long _ulong; typedef long long int lint; typedef pair plint; typedef pair pld; #define ALL(x) (x).begin(), (x).end() #define SZ(x) ((lint)(x).size()) #define FOR(i, begin, end) for(lint i=(begin),i##_end_=(end);i=i##_begin_;i--) #define REP(i, n) FOR(i,0,n) #define IREP(i, n) IFOR(i,0,n) #define endk '\n' templatebool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; } templatebool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; } lint gcd(lint a, lint b) { if (b == 0) return a; else return gcd(b, a % b); } lint ceil(lint a, lint b) { return (a + b - 1) / b; } lint digit(lint a) { return (lint)log10(a); } const lint MOD = 1e9 + 7, INF = 1e9; lint dx[8] = { 1, 0, -1, 0, 1, -1, 1, -1 }, dy[8] = { 0, 1, 0, -1, -1, -1, 1, 1 }; void YN(bool flag) { cout << (flag ? "YES" : "NO") << endk; } typedef pair Pa; typedef pair tlint; template struct Flow { struct edge { lint to; flow_t cap; cost_t cost; lint rev; }; vector > Graph; vector potential, min_cost; vector prevv, preve; vector level; vector iter; Flow(lint V) :Graph(V) {} void add_edge(lint from, lint to, flow_t cap, cost_t cost = 0) { Graph[from].push_back({ to, cap, cost, SZ(Graph[to]) }); Graph[to].push_back({ from, 0, -cost, SZ(Graph[from]) - 1 }); } void bfs(lint s) { lint V = SZ(Graph); level.assign(V, -1); queue que; que.push(s); level[s] = 0; while (!que.empty()) { lint v = que.front(); que.pop(); REP(i, SZ(Graph[v])) { edge& e = Graph[v][i]; if (e.cap > 0 && level[e.to] < 0) { level[e.to] = level[v] + 1; que.push(e.to); } } } } flow_t dfs(lint v, lint t, flow_t f) { if (v == t) return f; for (lint& i = iter[v]; i < SZ(Graph[v]); i++) { edge& e = Graph[v][i]; if (e.cap > 0 && level[v] < level[e.to]) { flow_t d = dfs(e.to, t, min(f, e.cap)); if (d > 0) { e.cap -= d; Graph[e.to][e.rev].cap += d; return d; } } } return 0; } flow_t max_flow(lint s, lint t) { flow_t flow = 0; lint V = SZ(Graph); for (;;) { bfs(s); if (level[t] < 0) return flow; iter.assign(V, 0); flow_t f; while ((f = dfs(s, t, INF)) > 0) { flow += f; } } } lint min_cost_flow(lint s, lint t, lint f) { cost_t res = 0; lint V = SZ(Graph); potential.assign(V, 0); prevv.assign(V, -1); preve.assign(V, -1); while (f > 0) { priority_queue, vector >, greater > > que; min_cost.assign(V, INF); min_cost[s] = 0; que.push({ 0, s }); while (!que.empty()) { pair p = que.top(); que.pop(); lint v = p.second; if (min_cost[v] < p.first) continue; REP(i, SZ(Graph[v])) { edge& e = Graph[v][i]; cost_t nextCost = min_cost[v] + e.cost + potential[v] - potential[e.to]; if (e.cap > 0 && min_cost[e.to] > nextCost) { min_cost[e.to] = nextCost; prevv[e.to] = v; preve[e.to] = i; que.push({ min_cost[e.to], e.to }); } } } if (min_cost[t] == INF) { return -1; } REP(v, V) potential[v] += min_cost[v]; flow_t addflow = f; for (lint v = t; v != s; v = prevv[v]) { addflow = min(addflow, Graph[prevv[v]][preve[v]].cap); } f -= addflow; res += addflow * potential[t]; for (lint v = t; v != s; v = prevv[v]) { edge& e = Graph[prevv[v]][preve[v]]; e.cap -= addflow; Graph[v][e.rev].cap += addflow; } } return res; } }; lint N; map mp; int main() { mp['y'] = 0; mp['u'] = 1; mp['k'] = 2; mp['i'] = 3; lint N; cin >> N; string str; cin >> str; vector arr(N); REP(i, N) { cin >> arr[i]; } lint s = 2 * N, t = s + 1; Flow g(2 * N + 2); REP(i, N) { if (str[i] == 'y') { g.add_edge(s, i, 1, 0); } if (str[i] == 'i') { g.add_edge(N + i, t, 1, 0); } FOR(j, i + 1, N) { if (mp[str[i]] + 1 == mp[str[j]]) { g.add_edge(N + i, j, 1, 0); } } } REP(i, N) { g.add_edge(i, i + N, 1, - arr[i]); } g.add_edge(s, t, N / 4, 0); cout << -g.min_cost_flow(s, t, N / 4) << endk; }