#pragma comment(linker, "/STACK:1024000000,1024000000")#include<cstdio>#include<cstring>#include<cmath>#include<algorithm>#include<vector>#include<map>#include<set>#include<queue>#include<stack>#include<iostream>using namespace std;typedef long long LL;const double pi=acos(-1.0),eps=1e-6;void File(){    freopen("D:\\in.txt","r",stdin);    freopen("D:\\out.txt","w",stdout);}template <class T>inline void read(T &x){    char c=getchar(); x=0;    while(!isdigit(c)) c=getchar();    while(isdigit(c)) {x=x*10+c-‘0‘; c=getchar();}}int n; LL m;struct X { LL x,y; }s[110];int main(){    while(~scanf("%d%lld",&n,&m))    {        map<LL,LL>dp;        for(int i=1;i<=n;i++) scanf("%lld%lld",&s[i].x,&s[i].y);             dp[0]=0; map<LL,LL>::iterator it;        for(int i=1;i<=n;i++)        {            it=dp.end(); --it;            for (; ; )            {                LL c=it->first, v=it->second;                if(c+s[i].x<=m) dp[c+s[i].x]=max(dp[c+s[i].x],dp[c]+s[i].y);                if(it==dp.begin()) break; --it;            }            it=dp.begin(); LL mx=0;            for (; it != dp.end(); )            {                if (it->second!=0&&it->second<=mx) dp.erase(it++);                else { mx=it->second; ++it; }            }        }        LL ans=0;  it=dp.begin();        for (; it != dp.end(); )        {            ans=max(ans,it->second);            ++it;        }        printf("%lld\n",ans);    }    return 0;}