#include <iostream>
#include <vector>
#include <algorithm>
#include <iostream>
#include <string>
#include <bitset>
#include <queue>
#include <fstream>
#include <stdio.h>
#include <string.h>
#include <iomanip>
#include <stack>
#include <climits>
#include <unordered_map>
#include <map>
#include <set>
using namespace std;

ifstream fin("rucsac.in");
ofstream fout("rucsac.out");

int dp[2][10001], n, G;
int v[5002], g[5002];
// dp[i][j] = val maxima pe care o pot obtine din primele i obiecte, avand greutatea totala j

int main()
{
	int i, j, p, s = 0, lin;
	fin >> n >> G;
	for (i = 1; i <= n; i++)
		fin >> g[i] >> v[i];
	lin = 1;
	dp[0][g[1]] = v[1];
	s += g[1];
	for (i = 2; i <= n; i++)
	{
		s += g[i];
		for (j = 0; j <= min(s, G); j++)
		{
			dp[lin][j] = dp[1 - lin][j];
			if (j >= g[i]) dp[lin][j] = max(dp[lin][j], dp[1-lin][j-g[i]] + v[i]);
		}
		lin = 1 - lin;
	}
	int ans = -1;
	for (j = 0; j <= G; j++)
		ans = max(ans, dp[1 - lin][j]);
	fout << ans;
	return 0;
}