//g++ 2.cpp -std=c++14 -O2 -I .
#include <bits/stdc++.h>
using namespace std;

#include <atcoder/all>
using namespace atcoder;

using ll = long long;
using ld = long double;

using vi = vector<int>;
using vvi = vector<vi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vld = vector<ld>;
using vvld = vector<vld>;
using vst = vector<string>;
using vvst = vector<vst>;

#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define pq_big(T) priority_queue<T,vector<T>,less<T>>
#define pq_small(T) priority_queue<T,vector<T>,greater<T>>
#define all(a) a.begin(),a.end()
#define rep(i,start,end) for(ll i=start;i<(ll)(end);i++)
#define per(i,start,end) for(ll i=start;i>=(ll)(end);i--)
#define uniq(a) sort(all(a));a.erase(unique(all(a)),a.end())

vvi dp(10050,vi(5050,0));

int main(){
  ios::sync_with_stdio(false);
  cin.tie(nullptr);

  int n,v,c;
  cin>>n>>v>>c;

  vector<pair<int,int>> gd(n);
  rep(i,0,n){
    int x,y;
    cin>>x>>y;
    gd[i]={x,y};
  }

  int ans=0;

  rep(i,0,n){
    auto [x,y]=gd[i];
    rep(j,0,v+1){
      dp[i+1][j]=dp[i][j]; 
      ans=max(ans,dp[i+1][j]);
    }
    per(j,v,0){
      if(j>=x){
        dp[i+1][j]=max(dp[i+1][j],dp[i][j-x]+y+c);
        ans=max(ans,dp[i+1][j]);
      }
    }
  }

  rep(i,0,n){
    auto [x,y]=gd[i];
    rep(j,0,v+1){
      dp[n+i+1][j]=dp[n+i][j]; 
      ans=max(ans,dp[n+i+1][j]);
    }
    rep(j,0,v+1){
      if(j+x<=v){
        dp[n+i+1][j+x]=max(dp[n+i+1][j+x],dp[n+i+1][j]+y);
        ans=max(ans,dp[n+i+1][j+x]);
      }
    }
  }

  cout<<ans<<endl;
}