#include<cstdio>
#include<algorithm>
const int MAXN=100000+10;
int n,h;
int a[MAXN],b[MAXN];
int ans;
int main(){
	scanf("%d%d",&n,&h);
	for(int i=0;i<n;i++)
		scanf("%d%d",&a[i],&b[i]);
	int x=*std::max_element(a,a+n);
	std::sort(b,b+n);
	std::reverse(b,b+n);
	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;
	}
	printf("%d\n",ans);
	return 0;
}