#include<bits/stdc++.h>
#define pb push_back
#define pli pair<int,int>
#define fi first
#define se second
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL);
using namespace std;
using ll=long long;
const ll maxn=2e5;
const ll inf=1e18;
const ll mod=1e15+37;
ll f[maxn]={0};
ll a,b,c;
vector<pli>g[2506][2506];
void dfs(ll x,ll y,ll h,ll v)
{
ll j=x+y-1;
f[j]=min(f[j],-y*h*a+c*h+b+v);
for(auto zz:g[x][y])
{
dfs(zz.fi,zz.se,h+1,v);
}
}
ll mu(ll a, ll b) {
ll k = (ll)((long double)a * b / mod);
ll r = a * b - mod * k;
if (r < 0) r += mod;
if (r >= mod) r -= mod;
return r;
}
string s;
ll hs[maxn],n,pw[maxn];
ll base=311;
ll get(ll i,ll j)
{
return (hs[j]-mu(hs[i-1],pw[j-i+1]) + mod) %mod;
}
struct qq
{
ll v,l,r;
bool operator<(const qq&o)
{
if(v==o.v) return l<o.l;
return v<o.v;
}
};
ll dp[2506][2506];
vector<qq> vec;
void solve()
{
cin >> n >> s >> a >> b >> c;
s=' '+s;
pw[0]=1;
for(int i=1;i<=n;i++)
{
hs[i]=(hs[i-1]*base+s[i])%mod;
pw[i]=pw[i-1]*base%mod;
}
for(int i=1;i<=n;i++)
{
for(int j=i;j<=n;j++)
{
vec.pb({get(i,j),i,j});
}
}
sort(vec.begin(),vec.end());
for(int i=0;i<vec.size();i++)
{
ll j=i;
vector<ll> pos;
while(j<vec.size()&&vec[i].v==vec[j].v)
{
pos.pb(vec[j].l);
j++;
}
ll len=vec[i].r-vec[i].l+1;
for(int q=pos.size()-1;q>=0;q--)
{
ll u=pos[q];
ll x=upper_bound(pos.begin(),pos.end(),u-len)-pos.begin()-1;
if(x>=0)
{
ll v=pos[x];
g[v][len].pb({u,len});
}
}
i=j-1;
}
for(int i=n;i>=1;i--)
{
for(int j=i;j<=n;j++)
{
if(i==j) dp[i][j]=a;
else
{
dp[i][j]=dp[i][j-1]+a;
dp[i][j]=min(dp[i][j],(j-i+1)*a+f[j]);
}
dfs(i,j-i+1,1,dp[i][j]);
}
}
cout << dp[1][n];
}
int main()
{
fastio
//freopen(TASKNAME".INP","r",stdin);
//freopen(TASKNAME".OUT","w",stdout);
solve();
}
