#include <bits/stdc++.h>
using namespace std;
#define all(x) x.begin(), x.end()
#define ar array
#define pb push_back
#define ln '\n'
#define int long long
using i64 = long long;
template <class F, class _S>
bool chmin(F &u, const _S &v){
bool flag = false;
if ( u > v ){
u = v; flag |= true;
}
return flag;
}
template <class F, class _S>
bool chmax(F &u, const _S &v){
bool flag = false;
if ( u < v ){
u = v; flag |= true;
}
return flag;
}
const int inf = 1e15;
const int Mod = 998244353;
struct _hash{
vector <int> pw, p;
_hash() : pw(1, 1) {}
void modify(string s, int P){
int n = s.size();
while ( pw.size() <= n ){
pw.pb(pw.back() * 1LL * P % Mod);
}
p.resize(n + 1);
for ( int i = 0; i < n; i++ ){
p[i + 1] = (p[i] * 1LL * P + s[i] - 'a' + 1) % Mod;
}
}
int get(int l, int r){
return (p[r + 1] - p[l] * 1LL * pw[r - l + 1] % Mod + Mod) % Mod;
}
};
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int n; cin >> n;
string s; cin >> s;
int A, B, C; cin >> A >> B >> C;
_hash h1, h2;
h1.modify(s, 31);
h2.modify(s, 47);
vector <vector<int>> nxt(n + 1, vector <int> (n));
for ( int l = 1; l <= n; l++ ){
map <pair<int,int>,int> lst;
for ( int i = n - l; i >= 0; i-- ){
int p = i, q = i + l - 1;
if ( q + l < n ){
lst[{h1.get(q + 1, q + l), h2.get(q + 1, q + l)}] = q + 1;
}
if ( lst.count({h1.get(p, q), h2.get(p, q)}) ){
nxt[l][i] = lst[{h1.get(p, q), h2.get(p, q)}];
} else{
nxt[l][i] = -1;
}
}
}
vector <vector<int>> dp(n, vector <int> (n, inf));
for ( int l = 1; l <= n; l++ ){
for ( int i = 0; i + l <= n; i++ ){
int p = i, q = i + l - 1;
chmin(dp[p][q], l * A);
if ( p + 1 <= q ){
chmin(dp[p][q], min(dp[p][q - 1], dp[p + 1][q]) + A);
}
int j = i, cnt = 1;
while ( (j = nxt[l][j]) != -1 ){
++cnt;
int r = j + l - 1;
chmin(dp[i][r], dp[p][q] + (r - i + 1 - l * cnt) * A + B + cnt * C);
}
}
}
cout << dp[0][n - 1];
cout << '\n';
}
