#if !__INCLUDE_LEVEL__

#include __FILE__

int main()
{
    ll N,V,C;cin >> N >> V >> C;
    vl Val(N);
    vl Wei(N);
    rep(i,N)cin >> Val[i] >> Wei[i];
    vvl DP(N+1,vl(V+1,-INF));
    DP[0][0] = 0;
    rep(i,N){
        rep(v,V+1){
            if(v+Val[i]<=V){
                chmax(DP[i+1][v+Val[i]],DP[i][v]+Wei[i]+C);
                chmax(DP[i+1][v+Val[i]],DP[i+1][v]+Wei[i]);
            }
            chmax(DP[i+1][v],DP[i][v]);
        }
        //cout << DP[i+1] << endl;
    }
    cout << maxv(DP[N]) << endl;
}

#else

#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
#define rep(i, n) for(int i = 0; i < n; i++)
#define rrep(i, n) for(int i = n; i >= 0; i--)
#define range(i, m, n) for(int i = m; i < n; i++)
#define fore(i,a) for(auto &i:a)
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define sum(v) accumulate(all(v),0)
#define minv(v) *min_element(all(v))
#define maxv(v) *max_element(all(v))
typedef long long ll;
typedef vector<ll> vl;
typedef vector<vector<ll>> vvl;
const ll INF = 1e16;
const ll MOD1 = 1000000007;
const ll MOD2 = 998244353;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
ll SN(char s){return ll(s-'0');}
ll SN(string s){return stoll(s);}
int alpN(char s){return int(s-'a');}
int AlpN(char s){return int(s-'a');}
using Graph = vector<vector<ll>>;
using mint1 = modint1000000007;
using mint2 = modint998244353;
template <class T>ostream &operator<<(ostream &o,const vector<T>&v){for(int i=0;i<(int)v.size();i++)o<<(i>0?" ":"")<<v[i];return o;}//vector空白区切り出力
ostream& operator<<(ostream& os, const mint1& N) {return os << N.val();}//mint出力。デフォはmint1
ostream& operator<<(ostream& os, const mint2& N) {return os << N.val();}
template<class T> bool contain(const std::string& s, const T& v) {
    return s.find(v) != std::string::npos;
}

#endif