#include<cstdio>
#include<algorithm>
#include<vector>
using namespace std; 
int main(){
	int N,H,a=0,b[100000],ans=0;
	scanf("%d%d",&N,&H);
	for(int i=0;i<N;i++){
		scanf("%d",b+i);
		a=max(a,b[i]);
		scanf("%d",b+i);
	}
	vector<int> v;
	for(int i=0;i<N;i++)
		if(b[i]>a)
			v.push_back(b[i]);
	sort(v.begin(),v.end());
	for(int i=v.size()-1;i>=0;i--){
		H-=v[i];
		ans++;
		if(H<=0){
			printf("%d",ans);
			return 0;
		}
	}
	printf("%d",ans+H/a+(bool)(H%a));
}