#include <bits/stdc++.h>
using namespace std;
int a[100010];
int b[100010];
int times, dmg;
int main() {
  int n, hp;
  cin >> n >> hp;
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
  }
  sort(a, a + n);
  sort(b, b + n);
  for (int i = n - 1; b[i] > a[n - 1]; i--) {
    times++;
    dmg += b[i];
  }
  hp -= dmg;
  cout << hp / a[n - 1] + (hp % a[n - 1] > 0) + times << endl;
  return 0;
}
