#include<bits/stdc++.h>
using namespace std;
const int N=300010,Len=log2(N)+1;
int n,m,st[N][Len+2];
long long w,st2[N][Len+2];
int maa,mia=1e9+1;
struct data
{
	int a,b;
}a[N];
map<long long,int> f,ys;
int ask1(int l,int r)
{
	int k=log2(r-l+1);
	return max(st[l][k],st[r-(1<<k)+1][k]);
}
long long ask2(int l,int r)
{
	int k=log2(r-l+1);
	return max(st2[l][k],st2[r-(1<<k)+1][k]);
}
bool cmp(data a,data b)
{
	return a.a<b.a;
}
int find(int x)
{
	int l=0,r=n+1,mid;
	while(l+1<r)
	{
		mid=(l+r)/2;
		if(a[mid].a<x)
			l=mid;
		else r=mid;
	}
	return a[r].a;
}
int find2(int x)
{
	int l=0,r=n+1,mid;
	while(l+1<r)
	{
		mid=(l+r)/2;
		if(a[mid].a<=x)
			l=mid;
		else r=mid;
	}
	return a[l].a;
}
bool check(int x)
{
//	cout<<":--"<<x<<"--:\n";
	int res=0;
	for(int i=1;i<=x;i++) 
	{
		int more=x-i+1;
		int l1=find(more);
		int r1=maa;
		long long ans1=ask1(ys[l1],ys[r1]);
		if(l1==0)ans1=0;
		
		int l2=mia;
		int r2=find2(more);
		long long ans2=ask2(ys[l2],ys[r2]);
		if(r2==0)ans2=0;
		
		res+=max(ans1*more,ans2);
//		cout<<l1<<" "<<r1<<" "<<l2<<" "<<r2<<" "<<ans1*more<<" "<<ans2<<" "<<res<<"\n";
	}
	return (res>=w);
} 
signed main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin>>n>>w;
	for(int i=1;i<=n;i++)
	{
		cin>>a[i].a>>a[i].b;
		if(!ys[a[i].a])ys[a[i].a]=++m;
		f[ys[a[i].a]]=max(f[ys[a[i].a]],a[i].b);
		st[ys[a[i].a]][0]=f[ys[a[i].a]];
		st2[ys[a[i].a]][0]=f[ys[a[i].a]]*a[i].b;
		maa=max(maa,a[i].a);
		mia=min(mia,a[i].a);
	}
	sort(a+1,a+n+1,cmp);
//	cout<<maa<<" "<<mia<<"\n";
	for(int j=1;j<=log2(n)+1;j++)
		for(int i=1;i+(1<<j)-1<=n;i++)
			st[i][j]=max(st[i][j-1],st[i+(1<<(j-1))][j-1]);
	for(int j=1;j<=log2(n)+1;j++)
		for(int i=1;i+(1<<j)-1<=n;i++)
			st2[i][j]=max(st2[i][j-1],st2[i+(1<<(j-1))][j-1]);
//	cout<<ask1(ys[a[1].a],ys[a[n].a])<<" "<<ask2(ys[a[1].a],ys[a[n].a])<<"\n";
	long long l=0,r=w/maa+1,mid;
	while(l+1<r)
	{
		mid=(l+r)/2;
		if(check(mid))r=mid;
		else l=mid;
	}
	cout<<r;
	return 0;
}