#include <bits/stdc++.h>
using namespace std;
unsigned long long n,b,sam=0,cnt,ty;
struct node
{
	long long p,c;
}a[100005];
bool cmp(node x,node y)
{
    if (x.p<y.p)return 1;
    else return 0;
}
int main()
{
	cin>>n>>b;
	for(int i=1;i<=n;i++) cin>>a[i].p>>a[i].c;
	sort(a+1,a+n+1,cmp);
	for(int i=1;i<=n;i++)
	{
		cnt=a[i].p*a[i].c;
		if(b>=cnt)
		{
			b=b-cnt;
			sam+=a[i].c;
		}
		else
		{
			while(b>=a[i].p)
			{
				b=b-a[i].p;
				sam++;
			}
			cout<<sam;
			return 0;
		}
	}
	cout<<sam;
	return 0;
}