#include <bits/stdc++.h>
#pragma optimize("Ofast")
#pragma target("avx2")
using namespace std;
#define ll long long
#define ld long double
#define pb push_back
#define pf push_front
#define pii pair<int,int>
#define all(v) v.begin(),v.end()
#define F first
#define S second
#define mem(a,i) memset(a,i,sizeof(a))
#define sz(s) (int)s.size()
#define y1 yy
#define ppb pop_back
#define lb lower_bound
#define ub upper_bound
#define gcd(a,b) __gcd(a,b)
#define in insert
// #define int ll
#define ull unsigned ll
const int MAX=2500+15;
const int B=331;
const int maxB=1000;
const int N=104;
const int block=450;
const ll inf=1e13;
const int mod=1e9+7;
const int mod1=1e9+9;
const ld eps=1e-9;
int dx[8]={1,0,-1,0,1,-1,-1,1};
int dy[8]={0,1,0,-1,1,-1,1,-1};
int binpow(int a,int n){
if(!n)return 1;
if(n%2==1)return a*binpow(a,n-1)%mod;
int k=binpow(a,n/2);
return k*k%mod;
}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int n,a,b,c;
string s;
const int L=3;
struct hash{
ll mod,C;
ll h[MAX],p[MAX];
void init(int module,int constant,string s){
mod=module;
C=constant;
p[0]=1;
for(int i=1;i<sz(s);i++){
h[i]=(h[i-1]*1ll*C+s[i])%mod;
p[i]=p[i-1]*1ll*C%mod;
}
}
int get(int l,int r){
return (h[r]-h[l-1]*1ll*p[r-l+1]%mod+mod)%mod;
}
}H[L];
struct pair_hash {
template <class T1, class T2>
std::size_t operator () (const std::pair<T1,T2> &p) const {
auto h1 = std::hash<T1>{}(p.first);
auto h2 = std::hash<T2>{}(p.second);
// Mainly for demonstration purposes, i.e. works but is overly simple
// In the real world, use sth. like boost.hash_combine
return h1 ^ h2;
}
};
ll dp[MAX][MAX];
int last[MAX][MAX];
unordered_map<pii,int,pair_hash> was;
struct segtree{
ll t[4*MAX];
int p[MAX];
void build(int v,int tl,int tr){
t[v]=inf;
if(tl==tr){
p[tl]=v;
return;
}
int tm=(tl+tr)/2;
build(2*v,tl,tm);
build(2*v+1,tm+1,tr);
}
void update(int pos,ll x){
int v=p[pos];
t[v]=x;
v/=2;
while(v){
t[v]=min(t[2*v],t[2*v+1]);
v/=2;
}
}
}t;
void solve(){
cin>>n>>s;
cin>>a>>b>>c;
s="#"+s;
H[0].init(1e9+7,331,s);
H[1].init(1e9+9,331,s);
H[2].init(998244353,331,s);
for(int zs=1;zs<=n;zs++){
for(int r=zs;r<=n;r++){
int R=r-zs;
int L=R-zs+1;
if(1<=L){
was[{H[0].get(L,R),H[1].get(L,R)}]=R;
}
int l=r-zs+1;
if(was.count({H[0].get(l,r),H[1].get(l,r)})){
last[l][r]=was[{H[0].get(l,r),H[1].get(l,r)}];
}
}
}
for(int i=1;i<=n;i++)dp[i][i]=a;
for(int r=2;r<=n;r++){
t.build(1,1,r);
vector<int> upd[r];
vector<int> cnt(r,0);
vector<ll> cost(r,0);
for(int l=r-1;l>=1;l--){
cost[r-l]=dp[l+1][r]+c-a*1ll*(r-l);
t.update(r-l,cost[r-l]);
if(last[l+1][r]-(r-l)+1>0)upd[last[l+1][r]-(r-l)+1].pb(r-l);
for(int zs:upd[l]){
cost[zs]+=(c-a*1ll*zs);
t.update(zs,cost[zs]);
if(last[l][l+zs-1]-zs+1>0)upd[last[l][l+zs-1]-zs+1].pb(zs);
}
dp[l][r]=min(dp[l][r-1]+a,t.t[1]+(r-l+1)*1ll*a+b);
}
}
// for(int zs=1;zs<=n;zs++){
// for(int l=1;l+zs-1<=n;l++){
// cout<<dp[l][l+zs-1]<<" ";
// }
// cout<<"\n";
// }
cout<<dp[1][n]<<"\n";
}
signed main(){
// freopen("triangles.in","r",stdin);
// freopen("triangles.out","w",stdout);
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
// prec();
int t=1;
// cin>>t;
while(t--)solve();
}
