#include <bits/stdc++.h>
using namespace std;
bool cmp(int a,int b){
	return a>b;
}

int main(){
	int n,h,i,move=0,mx=-1,s=0;
	cin>>n>>h;
	int a[n],b[n];
	for(i=0;i<n;i++){
		cin>>a[i]>>b[i];
		if (mx<a[i]) mx=a[i];
	}
	sort(b,b+n,cmp);
	for(i=0;i<n;i++){
		if (h<=0){
			cout<<i;
			return 0;
		}
		if(mx>=b[i]) break;
		h-=b[i];
	}
	if(h>0) move=(h-1)/mx+1;
	cout<<move+i;
}
