#include <bits/stdc++.h>
using namespace std;


class InParser {
private:
	FILE *fin;
	char *buff;
	int sp;

	char read_ch() {
		++sp;
		if (sp == 4096) {
			sp = 0;
			fread(buff, 1, 4096, fin);
		}
		return buff[sp];
	}

public:
	InParser(const char* nume) {
		fin = fopen(nume, "r");
		buff = new char[4096]();
		sp = 4095;
	}

	InParser& operator >> (int &n) {
		char c;
		while (!isdigit(c = read_ch()) && c != '-');
		int sgn = 1;
		if (c == '-') {
			n = 0;
			sgn = -1;
		} else {
			n = c - '0';
		}
		while (isdigit(c = read_ch())) {
			n = 10 * n + c - '0';
		}
		n *= sgn;
		return *this;
	}
};

int dp[5001][5001];
pair <int, int> v[50001];

int rec(int n, int g) {
    if(!n || !g || dp[n][g])
        return dp[n][g];
    if(v[n].first > g)
        return rec(n - 1, g);
    return dp[n][g] = max(rec(n - 1, g), rec(n - 1, g - v[n].first) + v[n].second);
}

int main() {
    InParser cin("rucsac.in");
    ofstream cout("rucsac.out");
    int n, g;
    cin >> n >> g;
    for(int i = 1; i <= n; i++) {
        cin >> v[i].first >> v[i].second;
    }
    cout << rec(n, g);
}