#include <stdio.h>
#include <iostream>
#include <string.h>
#include <stdlib.h>
#include <algorithm>
using namespace std;
int n,h,m=0,ans=0,a[111111],b[111111];
int main(){
	scanf("%d%d",&n,&h);
	for (int i=1;i<=n;i++){
		scanf("%d%d",&a[i],&b[i]);
		m=max(m,a[i]);
	}
	sort(b+1,b+n+1);
	for (int i=n;i&&b[i]>m&&h>0;i--){
		h-=b[i];
		ans++;
	}
	if (h>0){
	   ans+=(h+m-1)/m;
	}
	printf("%d",ans);
	return 0;
}