#include <bits/stdc++.h>
using namespace std;
 
using ll = long long;
 
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
 
    int n;
    ll W;
    if (!(cin >> n >> W)) return 0;
 
    vector<pair<ll,ll>> a(n);
    vector<ll> uniq;
    uniq.reserve(n);
    for (int i = 0; i < n; ++i) {
        cin >> a[i].first >> a[i].second;
        uniq.push_back(a[i].second);
    }
    sort(uniq.begin(), uniq.end());
    uniq.erase(unique(uniq.begin(), uniq.end()), uniq.end());
    int m = (int)uniq.size();
 
    vector<vector<ll>> g(m);
    for (int i = 0; i < n; ++i) {
        int id = int(lower_bound(uniq.begin(), uniq.end(), a[i].second) - uniq.begin());
        g[id].push_back(a[i].first);
    }
 
    vector<ll> base;
    for (int i = 0; i + 1 < m; ++i) base.push_back(uniq[i+1] / uniq[i]);
 
    vector<ll> cap(m, 0);
    ll rem = W;
    for (int i = 0; i + 1 < m; ++i) {
        cap[i] = rem % base[i];
        rem /= base[i];
    }
    cap[m-1] = rem;
 
    ll ans = 0;
    for (int i = 0; i < m; ++i) {
        auto &vec = g[i];
        if (!vec.empty()) sort(vec.begin(), vec.end(), greater<ll>());
        int s = (int)vec.size();
        vector<ll> pref(s+1, 0);
        for (int j = 0; j < s; ++j) pref[j+1] = pref[j] + vec[j];
 
        ll take = min<ll>(cap[i], s);
        ans += pref[(int)take];
 
        if (i + 1 < m) {
            int start = (int)take;
            ll k = base[i];
            int remCnt = s - start;
            int groups = remCnt / (int)k;
            for (int gidx = 0; gidx < groups; ++gidx) {
                int L = start + gidx * (int)k;
                int R = L + (int)k;
                g[i+1].push_back(pref[R] - pref[L]);
            }
        }
    }
 
    cout << ans << '\n';
    return 0;
}
 

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20 10000
222512691052 4096
5620511391 128
5142775228 64
197742659477 4096
525759354129 8192
19003783939 512
174609615733 4096
457491007 8
18306808974 256
990496677 16
4230766729 128
11201398381 256
73572867768 1024
8799846673 128
1968851699 32
6401370480 128
1010805215 16
64930386449 1024
54501354 1
288867560088 4096