#include <cstdio>
#include <cstring>
#include <algorithm>
#define ele int
using namespace std;
#define maxn 100010
ele n,h,a[maxn],b[maxn];
inline ele ceil(ele a,ele b){
	return (a%b)?(a/b+1):a/b;
}
int main(){
	scanf("%d%d",&n,&h);
	for (int i=0; i<n; ++i) scanf("%d%d",a+i,b+i);
	sort(a,a+n); sort(b,b+n);
	ele ans=1e9,tmp=h;
	for (int i=0; i<=n; ++i){
		ans=min(ans,i+ceil(tmp,a[n-1]));
		if (i<n) tmp-=b[n-1-i],tmp=max(tmp,0);
	}
	printf("%d\n",ans);
	return 0;
}