#include<bits/stdc++.h>
using namespace std;
int N,H;
int A[100005],B[100005];
int main()
{
	cin>>N>>H;
	for(int i=0;i<N;i++)
	cin>>A[i]>>B[i];
	int x=*max_element(A,A+N);
	sort(B,B+N);
	reverse(B,B+N);
	int ans=(H+x-1)/x;
	for(int i=0;i<N;i++)
	{
		H-=B[i];
		int tmp;
		if(H<=0)tmp=0;
		else tmp=(H+x-1)/x;
		if(ans>i+1+tmp)
			ans=i+1+tmp;
	}
	cout<<ans<<endl;
	return 0; 
}
