#include <bits/stdc++.h>
#define int long long
using namespace std;
template <const int32_t MOD> struct ModInt {
int32_t x;
ModInt() : x(0) {}
ModInt(long long u) : x(u % MOD) {
if (x < 0)
x += MOD;
}
friend bool operator==(const ModInt &a, const ModInt &b) {
return a.x == b.x;
}
friend bool operator!=(const ModInt &a, const ModInt &b) {
return a.x != b.x;
}
friend bool operator<(const ModInt &a, const ModInt &b) { return a.x < b.x; }
friend bool operator>(const ModInt &a, const ModInt &b) { return a.x > b.x; }
friend bool operator<=(const ModInt &a, const ModInt &b) {
return a.x <= b.x;
}
friend bool operator>=(const ModInt &a, const ModInt &b) {
return a.x >= b.x;
}
static ModInt sign(long long k) {
return ((k & 1) ? ModInt(MOD - 1) : ModInt(1));
}
ModInt &operator+=(const ModInt &m) {
x += m.x;
if (x >= MOD)
x -= MOD;
return *this;
}
ModInt &operator-=(const ModInt &m) {
x -= m.x;
if (x < 0LL)
x += MOD;
return *this;
}
ModInt &operator*=(const ModInt &m) {
x = (1LL * x * m.x) % MOD;
return *this;
}
friend ModInt operator-(const ModInt &a) {
ModInt res(a);
if (res.x)
res.x = MOD - res.x;
return res;
}
friend ModInt operator+(const ModInt &a, const ModInt &b) {
return ModInt(a) += ModInt(b);
}
friend ModInt operator-(const ModInt &a, const ModInt &b) {
return ModInt(a) -= ModInt(b);
}
friend ModInt operator*(const ModInt &a, const ModInt &b) {
return ModInt(a) *= ModInt(b);
}
static long long fp(long long u, long long k) {
long long res = 1LL;
while (k > 0LL) {
if (k & 1LL)
res = (res * u) % MOD;
u = (u * u) % MOD;
k /= 2LL;
}
return res;
}
static constexpr int mod() { return MOD; }
ModInt fastpow(long long k) { return ModInt(fp(x, k)); }
ModInt inv() {
assert(x);
return ModInt(fp(x, MOD - 2));
}
ModInt &operator/=(const ModInt &m) { return *this *= ModInt(m).inv(); }
friend ModInt operator/(const ModInt &a, const ModInt &b) {
return ModInt(a) *= ModInt(b).inv();
}
friend ostream &operator<<(ostream &out, const ModInt &a) {
return out << a.x;
}
friend istream &operator>>(istream &in, ModInt &a) { return in >> a.x; }
};
const int MOD = 1e9 + 9;
using Mint = ModInt<MOD>;
const int BASE = 330;
const int MAXN = 2501;
const int INF = 1e18;
Mint powBase[MAXN], invPow[MAXN];
signed main(void) {
ios_base::sync_with_stdio(false);
cin.tie(0);
powBase[0] = 1;
for (int i = 1; i < MAXN; ++i)
powBase[i] = powBase[i - 1] * BASE;
invPow[MAXN - 1] = powBase[MAXN - 1].inv();
for (int i = MAXN - 1; i > 0; --i)
invPow[i - 1] = invPow[i] * BASE;
int N, costAdd, costCut, costPaste;
string s;
cin >> N >> s >> costAdd >> costCut >> costPaste;
vector<Mint> prefPow(N + 1);
for (int i = 0; i < N; ++i)
prefPow[i + 1] = prefPow[i] + powBase[i] * s[i];
map<Mint, vector<int>> occs;
for (int deb = 0; deb < N; ++deb)
for (int fin = deb + 1; fin <= N; ++fin)
occs[(prefPow[fin] - prefPow[deb]) * invPow[deb]].push_back(deb);
vector<vector<int>> dp(N + 1, vector<int>(N + 1, INF));
for (int deb = N; deb >= 0; --deb)
for (int fin = deb; fin <= N; ++fin) {
int &cur = dp[deb][fin];
if (deb == fin) {
cur = 0;
continue;
}
cur = min(cur, dp[deb + 1][fin] + costAdd);
cur = min(cur, dp[deb][fin - 1] + costAdd);
for (int len = 1; len < fin - deb; ++len) {
Mint x = prefPow[deb + len] - prefPow[deb];
x *= invPow[deb];
auto &vec = occs[x];
int l = lower_bound(vec.begin(), vec.end(), deb) - vec.begin();
assert(vec[l] == deb);
int nbOcc = 0;
while (l < (int)vec.size()) {
int pos = vec[l];
if (pos + len > fin)
break;
nbOcc++;
while (l < (int)vec.size() and vec[l] - pos < len)
++l;
}
assert(len * nbOcc <= fin - deb);
cur = min(cur, (fin - deb - len * nbOcc) * costAdd + nbOcc * costPaste +
costCut + dp[deb][deb + len]);
}
}
cout << dp[0][N] << endl;
}
