#include <bits/stdc++.h>
#define int long long
#define cin ci
#define cout co
using namespace std;
ifstream cin("rucsac.in");
ofstream cout("rucsac.out");
const int inf = 1e9;
int n, g;
struct ob
{
    int price, weight;
};
vector<ob> v;
vector<int> dp;
int32_t main()
{
    cin >> n >> g;
    v.resize(n + 5);
    dp.resize(g + 5, -inf);
    for(int i = 1; i <= n; i++)
        cin >> v[i].weight >> v[i].price;
    dp[0] = 0;
    for(int i = 1; i <= n; i++)
        for(int j = g; j >= v[i].weight; j --)
            if(dp[j - v[i].weight] != -inf)
                dp[j] = max(dp[j], dp[j - v[i].weight] + v[i].price);
    int ans = -1;
    for(int i = 1; i <= g; i++)
        ans = max(ans, dp[i]);
    cout << ans;
    return 0;
}