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

int main(){
  int N,H; cin >> N >> H;
  int a[100000], b[100000];
  for(int i=0; i<N; i++){
    cin >> a[i] >> b[i];
  }
  sort(a,a+N,greater<int>());
  sort(b,b+N,greater<int>());
  int count=0;
  for(int i=0; i<N; i++){
    if(b[i]<=a[0]) break;
    if(H<=0) break;
    H-=b[i];
    count++;
  }
  if(H<=0) cout << count << endl;
  else{
    count+=(H+a[0]-1)/a[0];
    cout << count << endl;
  }
}