#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N=1e5+10;
pair< ll ,ll > a[N];
int main()
{
    int n;ll B;scanf("%d%lld",&n,&B);
    for(int i=1;i <= n;i++)scanf("%lld %lld", &a[i].first, &a[i].second);
    sort(a+1, a+n+1);
    ll ans=0;
    for(int i=1; i<=n;i++)
    {
        if(B / a[i].first < a[i].second)
        {
            ans+=B/a[i].first;
            break;
        }
        else
        {
            ans += a[i].second;
            B -= a[i].first * a[i].second;
        }
    }
    printf("%lld\n",ans);
    return 0;
}