#include<bits/stdc++.h>
using namespace std;
int main(void){
  int n, h; cin >> n >> h;
  vector<int> a(n), b(n);
  for(int i=0;i<n;i++) cin >> a[i] >> b[i];
  sort(a.begin(), a.end(), greater<int>());
  sort(b.begin(), b.end(), greater<int>());
  int i;
  for(i=0;i<n;i++){
    if (b[i] < a[0]) break;
    h -= b[i];
    if (h <= 0) {cout << 1+i << endl; return 0;}
  }
  cout << i + (h+a[0]-1)/a[0] << endl;
  return 0;
}
  
  
  