import java.util.*;
import java.io.*;
 
 
public class Main {
    public static void main(String[] args) throws Exception {
        FastScanner sc = new FastScanner();
        PrintWriter out = new PrintWriter(System.out);
        
        int n = sc.nextInt();
        int w = sc.nextInt();
        
        int[][] dt_in = new int[n][2];  //w,v
        
    	for(int i=0; i<n; i++){
    	    dt_in[i][1] = sc.nextInt();
    	    dt_in[i][0] = sc.nextInt();
    	}
    	combSort(dt_in, n);
    	ArrayList<Integer> selectedW = new ArrayList<>();
    	ArrayList<Integer> selectedValue = new ArrayList<>();
    	
    	int moving=dt_in[0][0], max_now=dt_in[0][1];
        for(int i=1; i<n; i++){
            if(dt_in[i][0] == moving){
                if(dt_in[i][1] > max_now) max_now = dt_in[i][1];
            }else{
                selectedW.add(moving);
                selectedValue.add(max_now);
                moving = dt_in[i][0];
                max_now=dt_in[i][1];
            }
        }
        selectedW.add(moving);
        selectedValue.add(max_now);
        n = selectedW.size();
        Integer[] value = selectedValue.toArray(new Integer[n]);
        Integer[] w_each = selectedW.toArray(new Integer[n]);
        
        
        int[][] dp = new int[n+1][w+1];
        
        for(int j=0; j<w; j++){
            dp[0][j] = 0;
        }
        
        int max_tmp = 0, c=0, tmp=0, wtmp=0;
    	for(int i=0; i<n; i++){
    	    wtmp = w_each[i];
    		for(int j=0; j<=w; j++){
    		    max_tmp = dp[i][j];
    		    c=1;
    		    while(j >= (wtmp*c)){
    		        tmp = dp[i][j - (w_each[i]*c)] + (value[i]*c);
    		        if(tmp > max_tmp) max_tmp = tmp;
    		        c++;
    		    }
    		    
    		    dp[i+1][j] = max_tmp;
    		}
    	}
        //show_i2d_array(dp);
        out.println(dp[n][w]);
        out.flush();
    }
    
    private static int max(int a, int b){
        if(a>b) return a;
        else return b;
    }
    
    
    static void show_i2d_array(int[][] dt){
        PrintWriter out = new PrintWriter(System.out);
    	for(int i=0; i<dt[0].length; i++){
    		for(int j=0; j<dt.length; j++){
    		    out.print(dt[j][i]+",");
    		}
    		out.println("<-w="+i);
    	}
    	out.flush();
    }
    
    public static void combSort(int[][] origin, int ln){
        int h=ln*10/13, tmp=0;
        boolean fin=true;
        while((h>1)||(!fin)){
            fin=true;
            for(int i=0; i < ln-h; i++){
                if(origin[i][0] > origin[i+h][0]){
                    tmp=origin[i][0];
                    origin[i][0]=origin[i+h][0];
                    origin[i+h][0]=tmp;
                    tmp=origin[i][1];
                    origin[i][1]=origin[i+h][1];
                    origin[i+h][1]=tmp;
                    fin=false;
                }
            }
            h *=10;
            h/=13;
        }
    }
}
 
class FastScanner {
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        }else{
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }
    
    private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
    private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
    public boolean hasNext() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; return hasNextByte();}
    public String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while(isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    public long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return minus ? -n : n;
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
    public int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException();
        return (int) nl;
    }
    public double nextDouble() { return Double.parseDouble(next());}
}


Measured memory_bytes: 30448