#include<stdio.h>
void quicksort(int a[],int s,int t){
  if(s<t){
    int i=s,j=t,p=a[(s+t)/2];
    while(1){
      while(a[i]>p)i++;
      while(p>a[j])j--;
      if(i>=j)break;
      a[i]^=a[j]^=a[i]^=a[j];
      i++;j--;
    }
    quicksort(a,s,i-1);quicksort(a,j+1,t);
  }
}
int main(){
  int n,h,a[100000],b[100000];
  scanf("%d%d",&n,&h);
  for(i=0;i<n;i++)scanf("%d%d",&a[i],&b[i]);
  quicksort(a,0,n-1);quicksort(b,0,n-1);
  i=0;while(b[i]>a[0]&&h>0&&i<n){h-=b[i];i++;}
  if(h>0)i+=(h+a[0]-1)/a[0];
  printf("%d",i);
}
