#include <bits/stdc++.h>
#define int long long
using namespace std;
const int N = 5e5 + 10;
priority_queue<int, vector<int>, greater<int>> q;
struct node { int v, m; } p[N];
int n, m, ans;
signed main() {
    freopen("Mining.in", "r", stdin);   
    freopen("Mining.out", "w", stdout); 
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    cin >> n >> m; int sum = 0;
    for (int i = 1; i <= n; i++) {
        cin >> p[i].v >> p[i].m;
        sum += p[i].m, ans += p[i].v;
    }
    if (sum <= m) {
        cout << ans << '\n';
        return 0;
    } else ans = 0;
    sort(p + 1, p + 1 + n, [&](node u, node v) {
        return u.m < v.m;
    });
    int bas = p[1].m, now = 0;
    m /= bas; 
    for (int i = 1; i <= n; i++) p[i].m /= bas;
    for (int i = 1, j = 1; i <= n; i = j) {
        while (j <= n && p[j].m == p[i].m) j++;
        if (p[i].m == 1) {
            for (int k = i; k < j; k++) {
                q.push(p[k].v);
            }
            while (q.size() > m) q.pop();
            now = m - q.size();
        } else {
            if (p[j].m > m) break;
            int rate = p[i].m / p[i - 1].m;
            vector<int> tmp;
            int rest = now % rate;
            now /= rate;
            while (q.size() + rest >= rate) {
                int sum = 0; 
                for (int _ = 1; _ <= rate - rest; _++) {
                    sum += q.top();
                    q.pop();
                }
                rest = 0;
                tmp.push_back(sum);
            }
            rest = 0;
            while (q.size()) {
                ans += q.top();
                q.pop();
            }
            for (auto v : tmp) q.push(v);
            for (int k = i; k < j; k++) {
                if (now) {
                    now--;
                    q.push(p[k].v);
                } else if (p[k].v > q.top()) {
                    q.pop();
                    q.push(p[k].v);
                }
            }
        }
    }
    while (q.size()) {
        ans += q.top();
        q.pop();
    }
    cout << ans << '\n';
    return 0;
}