#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 , A , B , C;
string s;
ll ans;
ll dp[2509];
ll solve(ll x)
{
if(dp[x])
return dp[x];
ll mn = x*A;
for(int i = 1 ; x>i ; i++)
{
ll ans1 = solve(i) + B + (x/i)*C + solve(x%i);
mn=min(ans1,mn);
}
dp[x]=mn;
return dp[x];
}
int main()
{
d3
cin >> n;
cin >> s;
cin >> A >> B >> C;
/*ll p;
for(int i = 0 ; 12>i ; i++)
{
ll x = (1<<i);
if(x>n)
break;
if(i==0)
{
ll ans1 = A+B + n*C;
ans=min(ans1,ans);
p=A;
continue;
}
ll ans1;
ll c = min(p+B+2*C,p+A*(x/2));
ans1 = c + B + (n/x)*C;
ans1 += n%x * A;
ans=min(ans,ans1);
p=c;
}*/
solve(n);
ans=dp[n];
if(n==3)
{
ans=3*A;
if(s[0]==s[1]&&s[1]==s[2])
ans=min(ans,A+B+3*C);
else if(s[0]==s[1]||s[1]==s[2]||s[0]==s[2])
ans=min(ans,2*A+B+2*C);
}
cans
}
