#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, a, b;
  cin >> n >> a >> b;
  string s;
  cin >> s;
  vector<pair<int, int>> pirs(n, {-1, -1});
  vector<int> sz(n, 0);
  int cnt = 0;
  for (int i = 0; i < n - 1; i++) {
    if (s[i] == s[n - 1]) {
      pirs[i] = {i, i};
      cnt = 1;
    }
  }
  sz[n - 1] = cnt;
  for (int i = n - 2; i > 0; i--) {
    for (int j = 0; j < i; j++) {
      if (s[i] == s[j]) {
        if (s[i + 1] == s[j + 1]) {
          if (pirs[j + 1].second == i) {
            pirs[j] = {j, i - 1};
            pirs[j + 1] = {-1, -1};
          } else {
            pirs[j] = {j, pirs[j + 1].second};
            pirs[j + 1] = {-1, -1};
          }
        } else
          pirs[j] = {j, j};
      } else
        pirs[j] = {-1, -1};
    }
    cnt = 0;
    for (int j = 0; j < i; j++) {
      if (pirs[j].first == j)
        cnt = max(cnt, pirs[j].second - pirs[j].first + 1);
    }
    sz[i] = cnt;
  }
  vector<long long> dp(n, 100000000000000000);
  dp[0] = (long long)a;
  for (int i = 1; i < n; i++) {
    dp[i] = min(dp[i], dp[i - 1] + (long long)a);
    for (int j = 0; j < sz[i]; j++)
      dp[i + j] = min(
          dp[i + j],
          dp[i - 1] + min(((long long)(j + 1)) * ((long long)a), (long long)b));
  }
  cout << dp[n - 1] << endl;
  return 0;
}
