#include <bits/stdc++.h>
using namespace std;
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  int n, h;
  cin >> n >> h;
  int memo = 0;
  int ans = INT_MAX;
  int a[n], b[n];
  vector<int> bt;
  int am = 0;
  int tmp;
  vector<int> nage;
  for (int i = 0; i < n; ++i) {
    cin >> a[i] >> b[i];
    am = max(am, a[i]);
  }
  for (int i = 0; i < n; ++i) {
    if (b[i] > am) {
      bt.push_back(b[i]);
    }
  }
  sort(bt.begin(), bt.end());
  for (int i = 0; i < bt.end() - bt.begin(); ++i) {
    h -= bt[i];
    if (h <= 0) {
      cout << i + 1 << endl;
      goto end;
    }
  }
  if (h % am == 0) {
    cout << h / am + bt.end() - bt.begin() << endl;
  } else {
    cout << h / am + 1 + bt.end() - bt.begin() << endl;
  }
end:
  return 0;
}
