#include <bits/stdc++.h>

using namespace std;

#define INF 1000000000
#define pb(a) push_back(a)
#define vi vector<int>
#define vvi vector<vi>
#define P pair<int,int>
#define all(vec) (vec.begin()),(vec.end())
#define ll long long
#define sz(x) ((int)(x).size())
#define in(x) int x;cin>>x;
#define bit(n) (1<<(n))

#define REP(i, n) for(int i=0, i##_len=(n); i<i##_len; ++i)
#define REPR(i, n) for(int i = n;i >= 0;i--)
#define REP3(i, m, n) for(int i = m, i##_len=(n);i < i##_len;i++)
#define FORVEC(i, v) for(int i = 0;i < sz(v);i++)


int main(){
	int n,h;
	int aa,bb;
	vi b;
	int ma=0;
	int cnt=0;
	cin>>n>>h;
	REP(i,n){
		cin>>aa>>bb;
		if(ma<aa)ma=aa;
		b.pb(bb);
	}
	sort(all(b),greater<int>());
	REP(i,n){
		if(ma<b[i]){
			h-=b[i];
			cnt++;
		}
		if(h<=0)break;
	}
	cout<<cnt+(h+ma-1)/ma<<"\n";
	return 0;
}
