#include <bits/stdc++.h>
#define int ll
using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
#define rng(i,x,n) for(int i=x;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define fi first
#define se second
#define pb push_back
#define sz(a) (int)a.size()
#define vec(...) vector<__VA_ARGS__>
#define _3rfKJyA ios::sync_with_stdio(0),cin.tie(0)
typedef long long ll;
using pii=pair<int,int>;
using vi=vector<int>;
void print(){cout<<'\n';}
template<class h,class...t>
void print(const h&v,const t&...u){cout<<v<<' ',print(u...);}
// e
//snuke's mod int
template <ll mod>
struct modint{
ll x; // typedef long long ll;
modint(ll x=0):x((x%mod+mod)%mod){}
modint operator-()const{return modint(-x);}
modint& operator+=(const modint a){if((x+=a.x)>=mod) x-=mod; return *this;}
modint& operator-=(const modint a){if((x+=mod-a.x)>=mod) x-=mod; return *this;}
modint& operator*=(const modint a){(x*=a.x)%=mod; return *this;}
modint operator+(const modint a)const{modint res(*this); return res+=a;}
modint operator-(const modint a)const{modint res(*this); return res-=a;}
modint operator*(const modint a)const{modint res(*this); return res*=a;}
modint pow(ll n)const{
modint res=1,x(*this);
while(n){
if(n&1)res*=x;
x*=x;
n>>=1;
}
return res;
}
modint inv()const{return pow(mod-2);}
};
// include mint here
using hshmint=modint<1000000007>;
using hshmint1=modint<998244353>;
using magicpair=pair<hshmint,hshmint1>;
struct rollhsh{
hshmint _p=9973; // base
hshmint1 _p1=257; // base1
vec(hshmint) pw,invpw;
vec(hshmint1) pw1,invpw1;
vec(magicpair) hsh;
rollhsh(string s=""){
init(s);
}
void init(string s){
// put this out in global if multiple testcases
hsh.clear();
pw.clear();
invpw.clear();
pw1.clear();
invpw1.clear();
hsh.resize(sz(s)+1);
pw.resize(sz(s)+1);
invpw.resize(sz(s)+1);
pw1.resize(sz(s)+1);
invpw1.resize(sz(s)+1);
hsh[0]={1,1};
pw[0]=1;
pw1[0]=1;
invpw[0]=1;
invpw1[0]=1;
hshmint _invbase=_p.x;
hshmint1 _invbase1=_p1.x;
_invbase=_invbase.inv(); _invbase1=_invbase1.inv();
rep(i,sz(s)){
pw[i+1]=pw[i]*_p;
pw1[i+1]=pw1[i]*_p1;
invpw[i+1]=invpw[i]*_invbase;
invpw1[i+1]=invpw1[i]*_invbase1;
hshmint x=(int)(s[i]-'a'+1);
hshmint1 x1=(int)(s[i]-'a'+1);
hsh[i+1]={hsh[i].fi+pw[i]*x,hsh[i].se+pw1[i]*x1};
}
}
pair<ll,ll> get(int l,int r){
// from - to , inclusive
hshmint _f=invpw[l]*(hsh[r+1].fi-hsh[l].fi);
hshmint1 _s=invpw1[l]*(hsh[r+1].se-hsh[l].se);
return {_f.x,_s.x};
}
};
signed main(){
_3rfKJyA;
int n;
cin>>n;
string s;
cin>>s;
int c0,c1,c2;
cin>>c0>>c1>>c2;
using pll=pair<ll,ll>;
std::map<pll,vi> mp;
rollhsh hsh(s);
rep(i,n){
rng(j,i,n){
mp[hsh.get(i,j)].pb(i);
}
}
vec(vi) nxt(n,vi(n,-1));
rep(i,n){
rng(j,i,n){
pll p=hsh.get(i,j);
auto it=upper_bound(mp[p].begin(),mp[p].end(),j);
if(it!=mp[p].end()){
nxt[i][j]=*it;
}
}
}
const int inf=numeric_limits<int>::max();
vec(vi) f(n,vi(n,inf)),g;
g=f;
for(int len=1;len<=n;len++){
for(int i=0;i<n;i++){
if(i+len-1>=n){
break;
}
int j=i+len-1;
if(len>1){
g[i][j]=min({g[i][j],g[i+1][j],g[i][j-1]});
}
f[i][j]=len*c0;
if(g[i][j]!=inf){
f[i][j]=min(f[i][j],len*c0+g[i][j]);
}
int cnt=1;
int nj=i;
while(1){
g[i][nj+len-1]=min(g[i][nj+len-1],-len*c0*cnt+cnt*c2+f[i][i+len-1]+c1);
nj=nxt[nj][nj+len-1];
if(nj==-1) break;
cnt+=1;
}
}
}
print(f[0][n-1]);
// // cout<<f[0][1]<<"\n";
//
return 0;
}
