#include <bits/stdc++.h> #define ll long long #define pii pair<int,int> using namespace std; const int MAX=2505; const int LOG=15; int N; ll CA,CB,CC; int A[MAX]; int up[MAX][MAX][LOG]; int nxt[MAX][MAX]; ll dp[MAX][MAX]; priority_queue<pii,vector<pii>,greater<pii>> pq; ll V[MAX]; int main(){ ios::sync_with_stdio(0);cin.tie(0); cin>>N; for (int i=0;i<N;i++){ char c;cin>>c; A[i]=c-'a'; } cin>>CA>>CB>>CC; for (int l=N-1;l>=0;l--){ int x; for (x=l+1;x<N;x++) if (A[x]==A[l]) break; up[l][l][0]=x; for (int r=l+1;r<N;r++){ while (x-l+r<N&&A[x-l+r]!=A[r]) x=up[x][x-l+(r-1)][0]; if (x-l+r>=N) x=N; up[l][r][0]=x; } } for (int k=1;k<LOG;k++) for (int l=0;l<N;l++) for (int r=l;r<N;r++){ int x=up[l][r][k-1]; if (x>=N) up[l][r][k]=N; else up[l][r][k]=up[x][x-l+r][k-1]; } for (int l=0;l<N;l++){ for (int r=l;r<N;r++){ int x=l; for (int k=LOG-1;k>=0;k--) if (x-l+r<N&&up[x][x-l+r][k]<=r) x=up[x][x-l+r][k]; nxt[l][r]=up[x][x-l+r][0]; } } for (int l=N-1;l>=0;l--){ while (pq.size()) pq.pop(); for (int r=l;r<N;r++){ dp[l][r]=min(dp[l+1][r]+CA,dp[l][r-1]+CA); while (pq.size()&&pq.top().first<=r){ auto [_,x]=pq.top(); pq.pop(); pq.push({nxt[r-x+l][r]-l+x,x}); V[x]+=CC-(x-l+1)*CA; dp[l][r]=min(dp[l][r],(r-l+1)*CA+V[x]); } V[r]=dp[l][r]+CB+CC-(r-l+1)*CA; pq.push({nxt[l][r]-l+r,r}); } } cout<<dp[0][N-1]<<'\n'; }