/**
____ ____ ____ ____ ____ ____
||l |||e |||i |||n |||a |||d ||
||__|||__|||__|||__|||__|||__||
|/__\|/__\|/__\|/__\|/__\|/__\|
**/
#include<bits/stdc++.h>
#define endl '\n'
using namespace std;
typedef long long ll;
void speed()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
}
const int maxn = 2510;
const ll base = 29, inf = 1e18;
int n;
ll a, b, c, h[maxn], pw[maxn];
string s;
vector < int > occ[maxn * maxn];
ll hs_dp[maxn * maxn], pt[maxn * maxn];
int nxt[maxn][maxn];
ll range_hash[maxn][maxn];
ll get_hash(int i, int j)
{
return range_hash[i][j];
}
unordered_map < ll, ll > rev;
void solve()
{
cin >> n >> s >> a >> b >> c;
s = "#" + s;
pw[0] = 1;
for (int i = 1; i <= n; i ++)
{
h[i] = h[i - 1] * base + (s[i] - 'a' + 1);
pw[i] = pw[i - 1] * base;
}
vector < ll > cp;
for (int i = 1; i <= n; i ++)
for (int j = i; j <= n; j ++)
{
range_hash[i][j] = h[j] - h[i - 1] * pw[j - i + 1];
cp.push_back(range_hash[i][j]);
}
///cp.erase(unique(cp.begin(), cp.end()), cp.end());
///sort(cp.begin(), cp.end());
int cnt = 0;
for (int i = 0; i < cp.size(); i ++)
{
if (rev[cp[i]] == 0)
rev[cp[i]] = i + 1;
}
for (int i = 1; i <= n; i ++)
for (int j = i; j <= n; j ++)
range_hash[i][j] = rev[range_hash[i][j]];
for (int i = n; i > 0; i --)
{
////cout << "------------" << endl;
for (int p = i; p <= n; p ++)
{
int cur_hs = range_hash[i][p];
occ[cur_hs].push_back(i);
/**cout << "hash " << i << " " << p << endl;
cout << "occurrences: ";
for (int ds : occ[cur_hs])
cout << ds << " ";
cout << endl;*/
if (occ[cur_hs].size() == 1)
{
hs_dp[cur_hs] = hs_dp[range_hash[i + 1][p]] + a;
nxt[p - i + 1][p] = n + 1;
pt[cur_hs] = -1;
}
else
{
hs_dp[cur_hs] = min(hs_dp[cur_hs], hs_dp[range_hash[i + 1][p]] + a);
if (pt[cur_hs] == -1)
{
pt[cur_hs] ++;
}
while(occ[cur_hs][pt[cur_hs]] > p)
pt[cur_hs] ++;
pt[cur_hs] --;
///cout << i << endl;
if (pt[cur_hs] == -1)
nxt[p - i + 1][p] = n + 1;
else
nxt[p - i + 1][p] = occ[cur_hs][pt[cur_hs]] + (p - i);
///cout << "step " << i << " " << p << " " << nxt[p - i + 1][p] << endl;
}
}
for (int k = i; k <= n; k ++)
{
int clip_hash, clip_len = k - i + 1;
clip_hash = get_hash(i, k);
ll cost = hs_dp[clip_hash] + b + c;
if (occ[get_hash(i, k)].size() < 2)
break;
int pos = k, pt = (int)(occ[clip_hash].size()) - 1;
///dp[get_hash(i, k)] = min(dp[get_hash(i, k)], cos);
//cout << "-------------------" << endl;
///cout << i << " " << k << endl;
while(pos <= n)
{
//cout << pos << " " << cost << endl;
int to = nxt[clip_len][pos];
if (to > n)
break;
cost = cost + (to - pos - clip_len) * a;
cost = cost + c;
///cout << "stop " << occ[clip_hash][pt] << endl;
///cost = cost + (occ[clip_hash][pt] - pos) * a;
///cost = cost + c;
pos = to;
hs_dp[range_hash[i][pos]] = min(hs_dp[range_hash[i][pos]], cost);
/**int to = pos + clip_len - 1;
if (to > n)
{
break;
}
if (get_hash(pos, to) == clip_hash)
{
cost = cost + c;
pos = pos + clip_len;
hs_dp[get_hash(i, to)] = min(hs_dp[get_hash(i, to)], cost);
}
else
{
pos ++;
cost += a;
}*/
}
}
for (int k = i; k <= n; k ++)
{
hs_dp[range_hash[i][k]] = min(hs_dp[range_hash[i][k]], hs_dp[range_hash[i][k - 1]] + a);
}
}
/**for (int i = 1; i <= n; i ++, cout << endl)
for (int j = i; j <= n; j ++)
cout << hs_dp[get_hash(i, j)] << " ";*/
cout << hs_dp[range_hash[1][n]] << endl;
}
int main()
{
solve();
return 0;
}
