#include <bits/stdc++.h>
using namespace std;
const int inf = 999999999;
const int mod = 1000000007;
const int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
int main() {
  int n, h;
  cin >> n >> h;
  int a_max = 0, max_n = 0, a[n], b[n], ans = 0;
  for (int i = (0); i < ((n)); i++) {
    cin >> a[i] >> b[i];
    if (a[i] > a_max) {
      max_n = i;
      a_max = a[i];
    } else if (a[i] == a_max) {
      if (b[max_n] < b[i]) {
        max_n = i;
      }
    }
  }
  vector<int> v;
  for (int i = (0); i < ((n)); i++) {
    if (b[i] > a_max && i != max_n) {
      v.push_back(b[i]);
    }
  }
  sort(v.begin(), v.end(), greater<int>());
  for (int i = (0); i < ((v.size())); i++) {
    h -= v[i];
    ans += 1;
    if (h <= 0) {
      cout << ans << endl;
      return 0;
    }
  }
  if (h > b[max_n])
    ans += (h - b[max_n] - 1) / a[max_n] + 2;
  else
    ans += 1;
  cout << ans << endl;
  return 0;
}
