CBUYING

#include <iostream>
#include <algorithm>
#include <numeric>
#include <set>
#include <queue>
#include <stack>
#include <vector>
#include <climits>
using namespace std;
const int N = 1e5;
struct T
{
    long long c, p;
    bool operator < (const T & other ) const
    {
        return p < other.p;
    }
};
T a[N+1];
long long n, sum = 0, b;
void read()
{
   cin >> n >> b;
   for (int i = 1; i <= n; ++ i)
   {
       cin >> a[i].p >> a[i].c;
   }
   sort(a + 1, a + n + 1);
}
void solve()
{
   for (int i = 1; i <= n; ++ i)
   {
       long long tmp = min(a[i].c, b/a[i].p);
       sum += tmp;
       b -= tmp * a[i].p;
   }
   cout << sum;
}
int main()
{
   ios_base::sync_with_stdio(false);
   cin.tie(nullptr);
   read();
   solve();
}