//luogu by zxr 2024.8.29

#include <bits/stdc++.h>
using namespace std;
const int N = 1e6 + 10;
int k[N], p[N], dp[N];

int main() {
	int n, R;
	cin >> n >> R;
	for (int i = 1; i <= n; i++) {
		cin >> k[i] >> p[i];
	}
	for (int i = 1; i <= n; i++) {
		for (int j = R; j >= p[i]; j--) {
			dp[j] = max(dp[j], dp[i - p[i]] + k[i]);
		}
	}
	cout << dp[R];

	return 0;
}