#include <bits/stdc++.h>
using namespace std;
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  int n, h;
  cin >> n >> h;
  int ans = INT_MAX;
  int a[n], b[n], bt[n];
  int am = 0;
  int tmp;
  vector<int> nage;
  for (int i = 0; i < n; ++i) {
    cin >> a[i] >> b[i];
    bt[i] = b[i];
    am = max(am, a[i]);
  }
  sort(bt, bt + n);
  nage.push_back(bt[n - 1]);
  for (int i = 1; i < n; i++) {
    if (nage[i - 1] + bt[n - i - 1] > h) {
      nage.push_back(h + 1);
    } else {
      nage.push_back(nage[i - 1] + bt[n - i - 1]);
    }
  }
  for (int i = max(0, (h - nage[n - 1]) / am); i <= 1000000000; ++i) {
    tmp = h - i * am;
    if (nage[n - 1] >= tmp) {
      vector<int>::iterator lit = lower_bound(nage.begin(), nage.end(), tmp);
      if (ans > lit - nage.begin() + 1 + i) {
        ans = lit - nage.begin() + 1 + i;
      }
    }
    if (am * i >= h) {
      ans = min(ans, i);
      break;
    }
  }
  cout << ans << endl;
  return 0;
}
