#include<cstdio>
#include<algorithm>
int main(){
	int n,h;
	scanf("%d%d",&n,&h);
	int a[n]={};
	int b[n]={};
	for(int i=0;i<n;i++){
		scanf("%d%d",&a[i],&b[i]);
	}
	std::sort(a,a+n);
	std::sort(b,b+n);
	int d=0;
	int ans=0;
	int p=0;
	for(int i=n-1;i>=0;i--){
		if(a[n-1]<b[i]){
			d+=b[i];
			ans++;
		}else{
			break;
			p=1;
		}
	}
	if(p==0)ans+=(h-d-1)/a[n-1]+1;
	printf("%d",ans);
	return 0;
}
	