#include <iostream>
#include <bits/stdc++.h>
#define ll long long
using namespace std;
const ll maxn = 2*1e5+5, INF = 4e18+9;
vector<int> z_function(string s) {
int n = s.size();
vector<int> z(n);
int l = 0, r = 0;
for(int i = 1; i < n; i++) {
if(i < r) {
z[i] = min(r - i, z[i - l]);
}
while(i + z[i] < n && s[z[i]] == s[i + z[i]]) {
z[i]++;
}
if(i + z[i] > r) {
l = i;
r = i + z[i];
}
}
return z;
}
void solve(){
int n;
cin >> n;
string s;
cin >> s;
s = ' ' + s;
ll A, B, C;
cin >> A >> B >> C;
auto chmin = [&](ll &a, ll b) -> void{
a = min(a, b);
};
vector<vector<ll>> f(n+2, vector<ll>(n+2, INF));
for(int i = 1; i <= n+1; i++){
f[i][i-1] = 0;
}
vector<vector<int>> link(n+1, vector<int>(n+1));
for(int l = n; l >= 1; l--){
vector<int> z(n+1, 0);
vector<int> t = z_function(s.substr(l, n-l+1));
for(int i = l; i <= n; i++){
z[i] = t[i-l];
}
int j = l;
for(int len = 1; len <= n-l+1; len++){
chmin(f[l][l+len-1], f[l+1][l+len-1] + A);
chmin(f[l][l+len-1], f[l][l+len-1-1] + A);
j = max(j, l+len);
while(j <= n && z[j] < len){
j++;
}
link[l][len] = j;
int r = link[l][len];
int cnt = 1;
while(r <= n){
cnt++;
chmin(f[l][r+len-1], f[l][l+len-1] + B + C * cnt + A * ((r+len-1 - l + 1) - (len*cnt)));
r = link[r][len];
}
}
}
cout << f[1][n];
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
solve();
}
