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

int main(void){
  int n,h;
  int a[100000],b[100000];

  scanf("%d %d",&n,&h);

  for(int i=0;i<n;i++){
    scanf("%d %d",&a[i],&b[i]);
  }

  sort(a,a+n);
  sort(b,b+n);

  int amax = a[n-1];
  int ans=0;
  int j = n-1;
  while(b[j]>amax&&h>0&&j>=0){
    h-=b[j];
    ans++;
    j--;
  }
  while(h>0){
    h-=amax;
    ans++;
  }

  printf("%d\n",ans);

  return 0;
}

