#include <bits/stdc++.h>
using namespace std;
long long n, d, a, b, p[100005], x[100005], y[100005], c, ans[100005];
long long cmp(long long A, long long B) {
  return x[A] * a + y[A] * b < x[B] * a + y[B] * b;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> n >> d;
  cin >> a >> b;
  for (long long i = 1; i <= n; i++) cin >> x[i] >> y[i], p[i] = i;
  sort(p + 1, p + 1 + n, cmp);
  for (long long i = 1; i <= n; i++)
    if (d >= x[p[i]] * a + y[p[i]] * b)
      d -= x[p[i]] * a + y[p[i]] * b, ans[++c] = p[i];
  cout << c << endl;
  for (int i = 1; i <= c; i++) cout << ans[i] << " ";
  cout << endl;
  return 0;
}
