#include <bits/stdc++.h>
using i64 = long long;
#ifdef DEBUG
#include "debug.h"
#else
#define debug(...) void(23)
#endif
constexpr i64 inf = i64(1E18);
constexpr int max_N = 2500 + 5;
i64 f[max_N][max_N];
bool chmin(i64& a, i64 b) {
if (a > b) {
a = b;
return true;
}
return false;
}
int nxt[max_N][max_N];
inline std::vector<int> Z(std::string s) {
int n = int(s.size());
std::vector<int> z(n);
for (int i = 1, j = 0; i < n; ++i) {
z[i] = std::max(0, std::min(j + z[j] - i, z[i - j]));
while (i + z[i] < n && s[z[i]] == s[i + z[i]]) {
z[i]++;
}
if (i + z[i] > j + z[j]) {
j = i;
}
#ifdef LOCAL
assert(s.substr(0, z[i]) == s.substr(i, z[i]));
#endif
}
return z;
}
int main() {
std::ios_base::sync_with_stdio(false);
std::cin.tie(nullptr);
std::fill_n(&f[0][0], max_N * max_N, inf);
std::fill_n(&nxt[0][0], max_N * max_N, max_N);
int N;
std::cin >> N;
std::string S;
std::cin >> S;
i64 A, B, C;
std::cin >> A >> B >> C;
auto g = [&](int l, int r) -> i64 {
return A * (r - l + 1);
};
for (int i = 0; i < N; ++i) {
std::string t = S.substr(i);
std::vector<int> z = Z(t);
int n = int(t.size()), p = 0;
for (int j = 0; j < n; ++j) {
for (int k = p; k < std::min(z[j], j); ++k) {
nxt[k + 1][i] = i + j;
++p;
}
}
}
#ifdef DEBUG
for (int i = 0; i < N; ++i) {
for (int k = 1; k <= N; ++k) {
std::cerr << nxt[k][i] << " \n"[k == N];
}
}
#endif
for (int i = 0; i < N; ++i) {
for (int j = 0; j < i; ++j) {
f[i][j] = 0;
}
}
for (int i = 0; i < N; ++i) {
f[i][i] = A;
}
for (int s = 0; s < N; ++s) {
for (int l = 0; l + s < N; ++l) {
int r = l + s;
if (l != r) {
chmin(f[l][r], f[l][r - 1] + A);
chmin(f[l][r], f[l + 1][r] + A);
}
int k = r - l + 1;
i64 now = f[l][l + k - 1] + B + C;
int rs = l;
debug(l, r, nxt[k][rs]);
while (nxt[k][rs] + k - 1 < N) {
int p = nxt[k][rs];
debug(p);
assert(rs + k <= p);
now += g(rs + k, p - 1) + C;
debug(l, p + k - 1, now);
chmin(f[l][p + k - 1], now);
rs = p;
}
}
}
#ifdef DEBUG
for (int i = 0; i < N; ++i) {
for (int j = i; j < N; ++j) {
debug(i, j, f[i][j]);
}
}
#endif
i64 ans = f[0][N - 1];
std::cout << ans << '\n';
return 0;
}
