#include <bits/stdc++.h>
using namespace std;

int main(){
  int n, h;
  int a[100001] = {};
  int b[100001] = {};
  cin >> n >> h;
  for(int i = 0; i < n; i++) cin >> a[i] >> b[i];
  sort(b, b+n); sort(a, a+n);
  int sum = 0;;
  for(int i = n-1; i >= 0; i--){
    if(h <= 0 || b[i] < a[n-1]) break;
    h -= b[i]; sum++;
  }
  if(h > 0){
    sum += h / a[n-1];
    sum += (h % a[n-1] > 0) ? 1 : 0;
  }
  cout << sum << endl;
  return 0;
}
