#include<bits/stdc++.h>

#define ll long long

#define rep2(i,a,b) for(int i=a;i>=b;i--)

#define rep(i,a,b) for(int i=a;i<=b;i++)

using namespace std;

const int maxn=;

char c[maxn],s[maxn];

struct SAM{

    int ch[maxn][],fa[maxn],maxlen[maxn],cnt,last;

    int a[maxn],b[maxn],occ[maxn];

    void init()

    {

        cnt=last=;

        memset(ch[],,sizeof(ch[]));

        memset(occ,0x3f,sizeof(occ));

    }

    int add(int x,int pos)

    {

       int np=++cnt,p=last; last=np;  occ[np]=pos;

       maxlen[np]=maxlen[p]+;memset(ch[np],,sizeof(ch[np]));

       while(p&&!ch[p][x]) ch[p][x]=np,p=fa[p];

       if(!p) fa[np]=;

       else {

         int q=ch[p][x];

         if(maxlen[q]==maxlen[p]+) fa[np]=q;

         else {

            int nq=++cnt; maxlen[nq]=maxlen[p]+;

            fa[nq]=fa[q]; fa[q]=fa[np]=nq;

            memcpy(ch[nq],ch[q],sizeof(ch[q]));

            while(p&&ch[p][x]==q) ch[p][x]=nq,p=fa[p];

         }

       }

    }

    void Sort()

    {

        rep(i,,cnt) a[i]=;

        rep(i,,cnt) a[maxlen[i]]++;

        rep(i,,cnt) a[i]+=a[i-];

        rep(i,,cnt) b[a[maxlen[i]]--]=i;

        for(int i=cnt;i>=;i--)

            occ[fa[b[i]]]=min(occ[b[i]],occ[fa[b[i]]]);

    }

}T;

int a[maxn],A,B,dp[maxn],pos[][];

int main()

{

    int N;

    scanf("%d%d%d%s",&N,&A,&B,c+);

    T.init();

    rep(i,,N) T.add(c[i]-'a',i);

    rep(i,,N) {

        int now=;

        rep(j,i,N){

            now=T.ch[now][c[j]-'a'];

            pos[i][j]=now;

        }

    }

    T.Sort();

    rep(i,,N){

        dp[i]=dp[i-]+A;

        rep(j,,i-){

            if(T.occ[pos[j+][i]]<=j){

                dp[i]=min(dp[i],dp[j]+B);

                break;

            }

        }

    }

    printf("%d\n",dp[N]);

    return ;

}