#include<iostream>
#include<fstream>
using namespace std;
ifstream in("rucsac.in");
ofstream out("rucsac.out");

int max(int a, int b) { return (a > b)? a : b; }  

int knapSack(int W, int wt[], int val[], int n)  
{  
if (n == 0 || W == 0)  return 0;
if (wt[n-1] > W)  return knapSack(W, wt, val, n-1);  
   else return max( val[n-1] + knapSack(W-wt[n-1], wt, val, n-1),  
                    knapSack(W, wt, val, n-1) );  
} 

int main(){
    int N,G;
	cin>>N>>G;
   int i;
   int w[50],p[50];
	for(i=0;i<N;i++) {
	in>>w[i]>>p[i];}
    out<<knapSack(G, w, p, N);
}