#include<bits/stdc++.h>
using namespace std;
using ll=long long;
using vec=vector<ll>;
using mat=vector<vec>;
#define For(i,a,b) for(i=a;i<b;i++)
#define rep(i,N) For(i,0,N)
#define rep1(i,N) For(i,1,N)
#define all(v) (v).begin(),(v).end()
#define allr(v) (v).rbegin(),(v).rend()
#define vsort(v) sort(all(v))
#define vrsort(v) sort(allr(v))
#define mod 1000000007
using datas=pair<ll,ll>;
using tdata=pair<datas,ll>;

long mmid(long a,long b,long c){return a<b?(b<c?b:max(a,c)):(b>c?b:min(a,c));}

ll modinv(ll a) {
  ll b=mod,u=1,v=0,t;
  while(b){
    t=a/b;
    a-=t*b; swap(a,b);
    u-=t*v; swap(u,v);
  }
  return (u+mod)%mod;
}

ll moddevide(ll a,ll b){return (a*modinv(b))%mod;}

ll modncr(ll n,ll r){
  ll i,plus=1;
  rep(i,r){
    plus=(plus*(n-i))%mod;
    plus=moddevide(plus,i+1);
  }
  return plus;
}

ll modncrlistp[200000],modncrlistm[200000];

ll modncrs(ll n,ll r){
  ll i,j;
  if(modncrlistp[n]==0){
    for(i=n;i>=0;i--){
      if(modncrlistp[i])break;
    }
    if(i<0){
      modncrlistp[0]=1;
      rep1(i,n+1){
        modncrlistp[i]=(modncrlistp[i-1]*i)%mod;
      }
    }else{
      For(j,i+1,n+1){
        modncrlistp[j]=(modncrlistp[j-1]*j)%mod;
      }
    }
  }
  if(modncrlistm[n]==0){
    for(i=n;i>=0;i--){
      if(modncrlistm[i])break;
    }
    if(i<0){
      modncrlistm[0]=1;
      rep1(i,n+1){
        modncrlistm[i]=(modncrlistm[i-1]*modinv(i))%mod;
      }
    }else{
      For(j,i+1,n+1)modncrlistm[j]=(modncrlistm[j-1]*modinv(j))%mod;
    }
  }
  return (((modncrlistp[n]*modncrlistm[r])%mod)*modncrlistm[n-r])%mod;
}

ll euclidean_gcd(ll a, ll b) {
  if(a<b) return euclidean_gcd(b, a);
  ll r;
  while ((r=a%b)){a=b;b=r;}
  return b;
}

ll countdigits(ll n){
  ll ans=0;
  while(n){n/=10;ans++;}
  return ans;
}

ll sumdigits(ll n){
  ll ans=0;
  while(n){ans+=n%10;n/=10;}
  return ans;
}

void printmap(vector<ll>& a,ll H,ll W){
  ll i,j;
  For(i,0,H+2){
    For(j,0,W+2){cout<<a[i*(W+2)+j];}
    cout<<endl;
  }
}
void inputmap(vector<ll>& a,ll H,ll W){
  ll i,j;
  string ss;
  For(i,1,H+1){
    cin>>ss;
    For(j,1,W+1){
      if(ss[j-1]=='#'){
        a[i*(W+2)+j]=1;
      }else{
        a[i*(W+2)+j]=0;
      }
    }
  }
}
ll lpow(ll a,ll b){
  ll i,res=1;
  rep(i,b){
    res*=a;
  }
  return res;
}

struct unionfind{
  vector<ll> par,treesize;
  unionfind(ll N){
    par.resize(N);
    for(ll i=0;i<N;i++)par[i]=i;
    treesize.resize(N);
    for(ll i=0;i<N;i++)treesize[i]=1;
  }
  ll root(ll x){
    ll r;
    if(par[x]==x)return x;
    r=root(par[x]);
    if(par[x]!=r){
      treesize[r]+=treesize[x];
      treesize[x]=0;
      par[x]=r;
    }
    return r;
  }
  void unite(ll x,ll y){
    ll px=root(x);
    ll py=root(y);
    if(px!=py){
      par[px]=py;
      treesize[py]+=treesize[px];
      treesize[px]=0;
    }
  }
  bool parcheck(ll x,ll y){
    ll px=root(x);
    ll py=root(y);
    return px==py;
  }
  ll size(ll x){
    ll px=root(x);
    return treesize[px];
  }
};
ll N;
ll dp[101][10001];

ll search(ll now,ll W,vector<datas>& v){
  if(dp[now][W]>=0)return dp[now][W];
  ll i,res=0;
  For(i,now+1,N){
    if(W>=v[i].second)res=max(res,v[i].first+search(i,W-v[i].second,v));
  }
  return dp[now][W]=res;
}

int main(){
  ll i,j,W=10001,ans=0;
  N=101;
  rep(i,N){
    rep(j,W){
      dp[i][j]=-1;
    }
  }
  cin>>N>>W;
  vector<datas> v(N);
  rep(i,N){
    cin>>v[i].first>>v[i].second;
  }
  rep(i,N){
    if(W>=v[i].second)ans=max(ans,v[i].first+search(i,W-v[i].second,v));
  }
  cout<<ans<<endl;
}


Measured memory_bytes: 11020