#include<stdio.h>
#include<algorithm>
using namespace std;
int n,h;
int a[100100];
int b[100100];
int main(){
  scanf("%d%d",&n,&h);
  int maxa=-1;
  for (int i=1;i<=n;i++){
      scanf("%d%d",&a[i],&b[i]);
    maxa=max(maxa,a[i]);
  }
  sort(b+1,b+n+1);
  int curIdx=n;
  int t=0;
  while(h>0){
    if (curIdx && b[curIdx]>maxa){
      h-=b[curIdx--];
      t++;
    }else{
      t+=h/maxa;
      if (h%maxa) t++;
      break;
    }
  }
  printf("%d\n",t);
  return 0;
}
