#include <bits/stdc++.h>
using namespace std;
template <typename S, typename T>
ostream& operator<<(ostream& out, const pair<S, T> p) {
  out << "(" << p.first << "," << p.second << ")";
  return out;
}
template <typename T>
ostream& operator<<(ostream& out, const vector<T>& v) {
  for (auto a : v) out << a << " ";
  return out;
}
template <typename T>
ostream& operator<<(ostream& out, const set<T>& S) {
  for (auto a : S) cout << a << " ";
  return out;
}
template <typename T>
ostream& operator<<(ostream& out, const multiset<T>& S) {
  for (auto a : S) cout << a << " ";
  return out;
}
template <typename S, typename T>
ostream& operator<<(ostream& out, const map<S, T>& M) {
  for (auto m : M) cout << "(" << m.first << "->" << m.second << ") ";
  return out;
}
template <typename S, typename T>
pair<S, T> operator+(pair<S, T> a, pair<S, T> b) {
  return make_pair(a.first + b.first, a.second + b.second);
}
template <typename S, typename T>
pair<S, T> operator-(pair<S, T> a, pair<S, T> b) {
  return make_pair(a.first - b.first, a.second - b.second);
}
vector<int> solve(string& str, int n, int x, int y) {
  vector<int> A;
  for (int i = 0; i <= n / x; i++) {
    if ((n - i * x) % y == 0) {
      for (int j = 0; j < i; j++) {
        A.push_back(x);
      }
      for (int j = 0; j < (n - i * x) / y; j++) {
        A.push_back(y);
      }
      return A;
    }
  }
  return A;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n, x, y;
  string str;
  cin >> n >> x >> y;
  cin >> str;
  vector<int> A = solve(str, n, x, y);
  if (A.empty()) {
    cout << -1 << endl;
  } else {
    int cur = 0;
    cout << A.size() << endl;
    for (int i = 0; i < A.size(); i++) {
      cout << str.substr(cur, A[i]) << '\n';
      cur += A[i];
    }
  }
  return 0;
}
