#include "bits/extc++.h"
using namespace std;
template <typename T>
void dbgh(const T& t) {
cerr << t << endl;
}
template <typename T, typename... U>
void dbgh(const T& t, const U&... u) {
cerr << t << " | ";
dbgh(u...);
}
#ifdef DEBUG
#define dbg(...) \
cerr << "L" << __LINE__ << " [" << #__VA_ARGS__ << "]" \
<< ": "; \
dbgh(__VA_ARGS__)
#else
#define cerr \
if (false) \
cerr
#define dbg(...)
#endif
#define endl "\n"
#define long int64_t
#define sz(x) int((x).size())
const long mod = 1e9 + 7;
long bpow(long base, long exp) {
long ans = 1;
while (exp) {
if (exp & 1) {
ans = (ans * base) % mod;
}
base = (base * base) % mod;
exp >>= 1;
}
return ans;
}
long inv(long x) {
return bpow(x, mod - 2);
}
struct Hasher {
int n;
vector<long> psum, ipow;
Hasher(const string& s, long base) : n(sz(s)), psum(n + 1), ipow(n + 1) {
ipow[0] = 1;
long ibase = inv(base), exp = 1;
for (int i = 0; i < n; i++) {
psum[i + 1] = (psum[i] + (s[i] - 'a' + 1) * exp) % mod;
exp = (exp * base) % mod;
ipow[i + 1] = (ipow[i] * ibase) % mod;
}
}
long hash(int l, int r) const {
return (psum[r] - psum[l] + mod) * ipow[l] % mod;
}
};
struct H {
Hasher h1, h2;
H(const string& s) : h1(s, 31), h2(s, 29) {}
long hash(int l, int r) const {
return h1.hash(l, r) * mod + h2.hash(l, r);
}
};
void solve1(int n, long wa, long wb, long wc) {
long dp[n + 1];
dp[0] = 0;
for (int i = 1; i <= n; i++) {
dp[i] = wa * i;
for (int j = 1; j < i; j++) {
int cnt = i / j;
dp[i] = min(dp[i], wa * i + dp[j] + wb + cnt * (wc - wa * j));
}
}
cout << dp[n] << endl;
}
void solve() {
int n;
cin >> n;
string s;
cin >> s;
long wa, wb, wc;
cin >> wa >> wb >> wc;
{
for (auto& a : s) {
if (a != 'a') {
goto loop;
}
}
solve1(n, wa, wb, wc);
return;
loop:;
}
H h(s);
pair<int, int> mp[n][n];
for (int i = 1; i <= n; i++) {
map<long, pair<int, int>> m;
for (int j = n - i; j >= 0; j--) {
mp[j][j + i - 1] =
m.emplace(h.hash(j, j + i), pair<int, int> {j, j + i - 1}).first->second;
}
}
long dp[n][n], mn[n];
memset(mn, 0x3f, sizeof(mn));
vector<pair<int, int>> occ[n][n];
for (int l = n - 1; l >= 0; l--) {
long copt = 0;
for (int r = l; r < n; r++) {
copt = min(copt + wa, wa * (r - l + 1) + mn[r]);
dp[l][r] = copt;
{
auto [il, ir] = mp[l][r];
int len = r - l + 1;
int nbs =
int(occ[il][ir].rend() - lower_bound(occ[il][ir].rbegin(), occ[il][ir].rend(),
pair<int, int> {l + len, -100})) -
1;
int ci = sz(occ[il][ir]), x = 0;
occ[il][ir].emplace_back(l, nbs);
while (ci != -1) {
auto [pos, nxt] = occ[il][ir][ci];
int np = pos + len - 1;
x++;
mn[np] = min(mn[np], dp[il][ir] + wb + x * (wc - wa * len));
ci = nxt;
}
}
}
}
cout << dp[0][n - 1] << endl;
}
int main() {
cin.tie(nullptr);
ios_base::sync_with_stdio(false);
cin.exceptions(ios::failbit);
solve();
}
