#include<bits/stdc++.h>
#include<atcoder/all>
using namespace std;
using namespace atcoder;
typedef long long int ll;
typedef long double ld;
#define FOR(i,l,r) for(ll i=l;i<r;i++)
#define REP(i,n) FOR(i,0,n)
#define RFOR(i,l,r) for(ll i=r-1;i>=l;i--)
#define RREP(i,n) RFOR(i,0,n)
#define ALL(x) x.begin(),x.end()
#define PA pair<ll,ll>
#define F first
#define S second
#define BS(A,x) binary_search(ALL(A),x)
#define LB(A,x) (ll)(lower_bound(ALL(A),x)-A.begin())
#define UB(A,x) (ll)(upper_bound(ALL(A),x)-A.begin())
#define COU(A,x) (UB(A,x)-LB(A,x))
#define sz(c) ((ll)(c).size())
//#include<boost/multiprecision/cpp_int.hpp>
//namespace mp=boost::multiprecision;
//using Bint=mp::cpp_int;
template<typename T>using min_priority_queue=priority_queue<T,vector<T>,greater<T>>;
template<class T>bool chmax(T&a,T b){if(a<b){a=b;return 1;}return 0;}
template<class T>bool chmin(T&a,T b){if(b<a){a=b;return 1;}return 0;}
template<class T>void print(vector<T>A){REP(i,A.size()){if(i)cout<<" ";cout<<A[i];}cout<<endl;}
ld dist(ld x1,ld y1,ld x2,ld y2){return sqrtl((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));}
//using mint=modint1000000007;
using mint=modint998244353;
//const ll mod=1000000007;
const ll mod=998244353;
//using mint=modint;
int main(){
  ll N,V,C;cin>>N>>V>>C;
  vector<ll>v(N),w(N);
  REP(i,N)cin>>v[i]>>w[i];
  vector<vector<ll>>DP(N+1,vector<ll>(V+1,-1e18));
  DP[0][0]=0;
  REP(i,N){
    DP[i+1]=DP[i];
    FOR(j,v[i],V+1){
      chmax(DP[i+1][j],C+DP[i][j-v[i]]+w[i]);
      chmax(DP[i+1][j],DP[i+1][j-v[i]]+w[i]);
    }
  }
  ll ans=0;
  REP(i,V+1)chmax(ans,DP[N][i]);
  cout<<ans<<endl;
  return 0;
}