rt

#include<bits/stdc++.h>
using namespace std;

struct cow{
	long long c,p;
}a[100005];
bool cmp(cow x,cow y){
	return x.p>y.p;
}
signed main(){
	int n;
	long long b;
	cin>>n>>b;
	for(int i=1;i<=n;i++){
		cin>>a[i].p>>a[i].c;
	}
	sort(a+1,a+1+n,cmp);
	int cnt=0;
	for(int i=1;i<=n;i++){
		if(b>=a[i].c*a[i].p){
			b-=a[i].c*a[i].p;
			cnt+=a[i].c;
		}else{
			int c=b/a[i].p;
			cnt+=c;
		}
	}
	cout<<cnt;
	return 0;
}