#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC target("sse4")
const long long LL_INF = 0x3f3f3f3f3f3f3f3f;
template <typename T>
T gcd(T a, T b) {
  if (a == 0) return b;
  return gcd(b % a, a);
}
long long power(long long a, long long b, long long m = 1000000007) {
  long long answer = 1;
  while (b) {
    if (b & 1) answer = (answer * a) % m;
    b /= 2;
    a = (a * a) % m;
  }
  return answer;
}
using namespace std;
void ctrl() { cout << "Control" << endl; }
long long make_num(string p) {
  stringstream geek(p);
  long long x = 0;
  geek >> x;
  return x;
}
string make_str(long long x) {
  ostringstream str1;
  str1 << x;
  string geek = str1.str();
  return geek;
}
vector<long long> z_function(string second) {
  long long n = (long long)second.length();
  vector<long long> z(n, 0);
  for (long long i = 1, l = 0, r = 0; i < n; ++i) {
    if (i <= r) z[i] = min(r - i + 1, z[i - l]);
    while (i + z[i] < n && second[z[i]] == second[i + z[i]]) ++z[i];
    if (i + z[i] - 1 > r) l = i, r = i + z[i] - 1;
  }
  return z;
}
signed main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cin.exceptions(cin.failbit);
  long long n, a, b;
  cin >> n >> a >> b;
  long long dp[n + 1];
  for (long long i = 1; i <= n; i++) dp[i] = 1000000007;
  string p;
  cin >> p;
  dp[0] = a;
  for (long long i = 1; i < n; i++) {
    dp[i] = min(dp[i], dp[i - 1] + a);
    vector<long long> vals = z_function(p.substr(i) + "$" + p.substr(0, i));
    for (long long j = n - i + 1; j < vals.size(); j++) {
      dp[i - 1 + vals[j]] = min(dp[i - 1 + vals[j]], dp[i - 1] + b);
    }
  }
  cout << dp[n - 1];
  return 0;
}
