#include<bits/stdc++.h>
using namespace std;
const int N=30005;
long long n,m,f[N]={0},s=0,w[1001]={0},wz[101]={0},vz[101]={0},zl=0;
int main()
{
    freopen("delicious.in","r",stdin);
    freopen("delicious.out","w",stdout);
    cin>>n>>m;
    for(int i=1;i<=n;i++)
    {
        int x,y;
        cin>>x>>y;
        if(w[x]==0)
        {
            wz[++zl]=x;
            vz[zl]=y;
        }
        w[x]++;
    }
    for(int i=1;i<=zl;i++)
    {
        for(int k=1;k<=w[wz[i]];k++)
        for(int j=m;j>=wz[i];j--)
        f[j]=max(f[j],f[j-wz[i]]+vz[i]);
    }
    cout<<f[m]<<endl;
    return 0;
}