// Success consists of going from failure to failure without loss of enthusiasm
#include <bits/stdc++.h>
using namespace std;
#define nl '\n'
#define pb push_back
#define f first
#define s second
#define mp make_pair
#define sz(x) int(x.size())
using pi = pair<int, int>;
using ll = long long;
template<class T> using V = vector<T>;
using vi = V<int>;
using vl = V<ll>;
using vpi = V<pi>;
using str = string;
const int MOD = 1e9 + 9;
const ll b1 = 2003;
const ll b2 = 1009;
const ll INFL = ll(4e18);
const int LG = 18;
int main() {
cin.tie(0)->sync_with_stdio(0);
int N; cin >> N;
str S; cin >> S;
ll a, b, c; cin >> a >> b >> c;
V<vl> dp(N, vl(N, INFL));
V<vi> nxt(N, vi(N, -1));
for(int l = 0; l < N; l++) for(int r = l; r < N; r++) dp[l][r] = (r - l + 1) * a;
unordered_map<ll, int> C;
V<V<vi>> H(N);
for(int l = 0; l < N; l++) {
ll h1 = 0, h2 = 0;
for(int w = 0; l + w < N; w++) {
h1 = (b1 * h1 + S[l + w]) % MOD;
h2 = (b2 * h2 + S[l + w]) % MOD;
// cout << l << " " << w << " " << h << endl;
ll h = MOD * h1 + h2;
if (C.find(h) == C.end()) C[h] = sz(H[w]), H[w].pb({});
H[w][C[h]].pb(l);
}
}
for(int w = 0; w < N; w++) {
// cout << w << endl;
for(auto& v : H[w]) {
// for(auto& x : v) cout << x << " ";
// cout << endl;
v.pb(-1);
int j = sz(v) - 1;
for(int i = sz(v) - 2; i >= 0; i--) {
while(j - 1 >= 0 && (v[i] + w) < v[j - 1]) j--;
nxt[v[i]][v[i] + w] = v[j];
}
}
// cout << endl;
}
// for(int l = 0; l < N; l++) for(int r = l; r < N; r++) {
// if (nxt[l][r] >= MOD) nxt[l][r] = -1;
// // cout << l << " " << r << " " << nxt[l][r] << endl;
// }
for(int w = 0; w < N; w++) {
for(int l = 0; l + w < N; l++) {
int r = l + w;
if (r-1 >= 0) dp[l][r] = min(dp[l][r], dp[l][r-1] + a);
if (l+1 < N) dp[l][r] = min(dp[l][r], dp[l+1][r] + a);
// cout << l << " " << r << " " << dp[l][r] << endl;
int L = l; ll amt = 1;
while(nxt[L][L + w] != -1) {
L = nxt[L][L + w], amt++;
ll left = (L + w - l + 1) - (l + w - l + 1) * amt;
dp[l][L + w] = min(dp[l][L + w], dp[l][r] + b + c * amt + left * a);
// cout << l << " " << l + w << " " << L << " " << L + w << " => " << dp[l][L + w] << endl;
}
}
}
cout << dp[0][N-1] << nl;
exit(0-0);
}
