#include<iostream>
#include<algorithm>
using namespace std;

int main() {
  int N, H;
  int a[100000], b[100000];
  cin >> N >> H;
  int max_a = 0;
  for(int i = 0; i < N; i++) {
    cin >> a[i] >> b[i];
    if(a[i] > max_a) max_a = a[i];
  }
  sort(b, b + n);
  int cnt = 0;
  for(int i = 0; i < N; i++){
    if(b[i] > max_a){
      cnt++;
      H -= b[i];
    }
    if(H <= 0){
      cout << cnt << endl;
      return 0;
    }
  }
  if(H % max_a == 0) cout << cnt + H / max_a << endl;
  else cout << cnt + H / max_a + 1 << endl;
  return 0;
}