#include<bits/stdc++.h>
#define ll long long
#define F first
#define S second
#define in insert
#define pb push_back
#define ppb pop_back()
#define d3 ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define cans cout << ans << "\n";
#define yes cout << "Yes" << "\n";
#define no cout << "No" << "\n";
#define pll pair<ll,ll>
#define lin cout << "\n";
#define sqr 340
#define mod 1000000007
#define mid ((l+r)/2)
#define lc (2*x)
#define rc (2*x+1)
using namespace std;
ll n;
string s;
ll A , B , C;
bitset<1600000090> e;
ll dp[209][209];
vector<ll> idx[1009][1009];
ll fp(ll x , ll y)
{
if(y==0)
return 1;
ll z = fp(x,y/2);
if(y&1)
return z*z%mod*x%mod;
else
return z*z%mod;
}
ll gt(ll i , ll j , ll l1 , ll r1)
{
ll l = 0 , r = idx[i][j].size()-1;
ll sum = 0;
while(l<=r)
{
if(idx[i][j][mid]>r1)
r=mid-1;
else
{
sum=mid+1;
l=mid+1;
}
}
sum*=(j-i+1);
return sum;
}
ll solve(ll l , ll r)
{
if(dp[l][r])
return dp[l][r];
ll ans = (r-l+1)*A;
for(ll i = l ; r>i ; i++)
{
for(ll j = i ; r>j ; j++)
{
ll ans1 = solve(i,j) + B + (i-l)*A + C;
ll y = gt(i,j,j+1,r);
ans1+=y/(j-i+1)*C;
ans1+=(r-j-y)*A;
ans=min(ans,ans1);
}
}
dp[l][r]=ans;
return ans;
}
int main()
{
mt19937 rnd(time(0));
cin >> n;
cin >> s;
cin >> A >> B >> C;
ll p = rnd();
for(int l = 1 ; n>=l ; l++)
{
map<ll,pll> mp;
ll hsh = 0;
ll pr = 1;
for(int i = n-l ; i>n-2*l ; i--)
{
ll y = int(s[i]);
hsh+=y*pr;
hsh%=mod;
pr*=p;
pr%=mod;
}
mp[hsh]={n-2*l+1,n-l};
pr=fp(p,l-1);
for(int j = n-l-1 ; j>=0 ; j--)
{
int i = j-l+1;
ll y = int(s[j+1]);
hsh-=y;
hsh%=mod;
hsh+=mod;
hsh%=mod;
hsh*=fp(p,mod-2)%mod;
y=int(s[i]);
hsh+=y*pr;
hsh%=mod;
if(mp[hsh].F!=0)
{
idx[i][j]=idx[mp[hsh].F][mp[hsh].S];
if(mp[hsh].F>j)
idx[i][j].pb(mp[hsh].S);
}
mp[hsh]={i,j};
}
}
for(int i = 0 ; n>i ; i++)
for(int j = i ; n>j ; j++)
reverse(idx[i][j].begin(),idx[i][j].end());
ll ans = solve(0,n-1);
cans
}
