#include <bits/stdc++.h>
using namespace std;

int main()
{
    // 入力
    int N,H;
    cin>>N>>H;
    int a,b[N];
    int a_max=0;
    for(int i=0;i<N;i++){
    	cin>>a;
    	a_max=max(a,a_max);
    	cin>>b[i];
    }
    int max_turn=0;
    sort(b,b+N);
    for(int i=N-1;i>=0;i--){
    	if(H<=0 || b[i]<a_max) break;
    	max_turn++;
    	H-=b[i];
    }

    if(H>0) max_turn+= (H+a_max-1)/a_max;
    cout<<max_turn<<endl;

    return 0;
}