#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using ll=long long;
using Graph=vector<vector<int>>;
#define MAX 3000
//#define MOD 1000000007
#define MOD 998244353
#define INF 1000000000
//#define INF 1000000000000000000

int main(){
  int N,V,C;
  cin>>N>>V>>C;
  vector<int> v(N),w(N);
  for(int i=0;i<N;i++){
    cin>>v[i]>>w[i];
  }

  vector<int> dp(V+1,0);
  for(int i=0;i<N;i++){
    for(int j=V-v[i];j>=0;j--){
      dp[j+v[i]]=max(dp[j+v[i]],dp[j]+w[i]+C);
    }
    for(int j=0;j<=V-v[i];j++){
      dp[j+v[i]]=max(dp[j+v[i]],dp[j]+w[i]);
    }
  }
  cout<<dp[V]<<'\n';
}