#include<bits/stdc++.h>
#define int long long
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define per(i,a,b) for(int i=(a);i>=(b);i--)
#define fi first
#define se second
#define eb emplace_back
#define popc __builtin_popcount
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<pii> vp;
typedef unsigned long long ull;
typedef long double ld;

int read() {
  int x=0,w=1; char c=getchar(); 
  while(!isdigit(c)) {if(c=='-') w=-1; c=getchar();}
  while(isdigit(c)) {x=x*10+(c-'0'); c=getchar();}
  return x*w;
}

const int N=7009,M=4e6+9,inf=0x3f3f3f3f3f3f3f3f;

int n,A,B,C,ch[M][27],cnt,tot=1,a[N],nxt[N][N],deg[M],len[N],dep[M],fl[N],c[N][N],dp[N];
char s[N];
map<pii,int>id[N];
vi f[M];

void ins(int l) {
  int p=1;
  rep(r,l,n) {
    if(!ch[p][a[r]]) ch[p][a[r]]=++tot;
    p=ch[p][a[r]]; f[p].eb(l); dep[p]=r-l+1;
  } ch[p][0]=1;
}

int dfs(int i) {
  if(dp[i]) return dp[i]; dp[i]=len[i]*A;
  int tmp=0;
  rep(j,1,cnt) if(i!=j&&c[i][j]>1) {
    int r=(len[i]-len[j]*c[i][j])*A+B+C*c[i][j];
    if(dfs(j)+r<dp[i]) tmp=j;
    dp[i]=min(dp[i],dfs(j)+r);
  }
  return dp[i];
}

signed main() {
  scanf("%lld%s%lld%lld%lld",&n,s+1,&A,&B,&C);
  rep(i,1,n) a[i]=s[i]-'a'+1; s[n+1]=0;
  per(i,n,1) ins(i);
  rep(i,2,tot) {
    rep(c,0,26) deg[i]+=(ch[i][c]>0); int sz=f[i].size();
    bool flag=(deg[i]>1)||(dep[i]==n);
    sort(f[i].begin(),f[i].end());
    rep(j,1,sz-1) if(f[i][j]==f[i][j-1]+dep[i]) flag=1;
    if(flag) {
      ++cnt; fl[cnt]=f[i][0]; len[cnt]=dep[i];
      for(auto l:f[i]) nxt[cnt][l]=l;
      per(j,n,1) if(!nxt[cnt][j]) nxt[cnt][j]=nxt[cnt][j+1];
      rep(j,1,2*n) if(!nxt[cnt][j]) nxt[cnt][j]=n+1;
    }
  }
  rep(i,1,cnt) {
    rep(j,1,cnt) if(len[i]>len[j]) {
      int pos=fl[i]; pos=nxt[j][pos];
      while(pos+len[j]-1<=fl[i]+len[i]-1) ++c[i][j], pos=nxt[j][pos+len[j]];
    }
  }
  printf("%lld\n",dfs(cnt));
  return 0;
}