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

const int N = 1e5+10;
int a[N],b[N];

signed main(){

  int n,h;  cin >> n >> h;
  for(int i = 0; i < n; i++){
    cin >> a[i] >> b[i];
  }

  sort(a,a+n),sort(b,b+n);
  int cnt = 0;
  for(int i = n-1; a[n-1] <= b[i]; i--){
    h -= b[i];
    cnt++;
    if(h <= 0) break;
  }
  if(h > 0) cnt += (h+a[n-1]-1)/a[n-1];
  cout << cnt << endl;

  return 0;
}
