#include <bits/stdc++.h>
using namespace std;
#define int long long
signed 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<vector<int>> dp(N+1,vector<int>(V+1));
  for(int i=1;i<=N;i++){
    for(int j=0;j<=V;j++){
      int ans = dp[i-1][j];
      if(v[i-1] <= j) ans = max(max(ans,dp[i][j-v[i-1]]+w[i-1]),dp[i-1][j-v[i-1]]+w[i-1]+C);
      dp[i][j] = ans;
    }
  }
  int ans = -1;
 /*for(int i=0;i<=N;i++){
    for(int j=0;j<=V;j++){
      cout<<dp[i][j]<<' ';
    }
    cout<<endl;
  }*/
  for(int i=0;i<=V;i++) ans = max(ans,dp[N][i]);
  cout<<ans<<endl;
}