#include<bits/stdc++.h>
using namespace std;
#define N 30005
typedef long long ll;
int n,m,w[N],v[N],g[N],f[N],sum,ww[N],vv[N],summ;

int read(){
	int w=0,f=1;
	char c=getchar();
	while (c>'9'||c<'0'){
		if (c=='-') f=-1;
		c=getchar();
	}
	while (c>='0'&&c<='9'){
		w=(w<<3)+(w<<1)+(c^48);
		c=getchar();
	}
	return w*f;
}
int main(){
	freopen("delicious.in","r",stdin);
	freopen("delicious.out","w",stdout);
	n=read(),m=read();
	for (int i=1;i<=n;i++){
		int x=read(),y=read();
		bool pd=0;
		for (int j=1;j<=sum;j++){
			if (x==w[j]&&y==v[j]) g[j]++,pd=1;
		}
		if (pd==0){
			w[++sum]=x,v[sum]=y,g[sum]=1;
		}
	}
	for (int i=1;i<=sum;i++){
		int a=1;
		while (g[i]-a>=0){
			ww[++summ]=w[i]*a,vv[summ]=v[i]*a;
			g[i]-=a;
			a<<=1;
		}
		if (g[i]>0) ww[++summ]=w[i]*g[i],vv[summ]=v[i]*g[i];
	}
	for (int i=1;i<=summ;i++){
		for (int j=m;j>=w[i];j--){
			f[j]=max(f[j],f[j-w[i]]+v[i]);
		}
	}
	printf("%d\n",f[m]);
	return 0;
}