#include <bits/stdc++.h>
using namespace std;
long long inf = 2147483647;
const long long ll = 9223372036854775807, ninf = 1000000000;
const double eps = 1e-6;
const long long nll = 1000000000000000000;
class MagicNumberThree {
 public:
  int countSubsequences(string s) {}
};
int main() {
  int a, b;
  while (cin >> a >> b) {
    int maxr = 0;
    int ans = 0;
    vector<int> B;
    for (int i = 0; i < a; i++) {
      int x, y;
      cin >> x >> y;
      maxr = max(maxr, x);
      B.push_back(y);
    }
    sort(B.begin(), B.end());
    for (int i = B.size() - 1; i >= 0 && b > 0; i--) {
      ans++;
      b -= B[i];
    }
    if (b > 0) {
      ans += b / maxr;
      b %= maxr;
      if (b) ans++;
    }
    cout << ans << '\n';
  }
  return 0;
}
