#include<bits/stdc++.h>
using namespace std;
#include <unordered_set>
#include <random>
//#define int long long
#define REP(i,m,n) for(int i=(m);i<(n);i++)
#define rep(i,n) REP(i,0,n)
#define pb push_back
#define all(a) a.begin(),a.end()
#define rall(c) (c).rbegin(),(c).rend()
#define mp make_pair
#define endl '\n'
//#define vec vector<ll>
//#define mat vector<vector<ll> >
#define fi first
#define se second
#define double long double
typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll,ll> pll;
//typedef long double ld;
typedef complex<double> Complex;
const ll INF=1e9+7;
const ll MOD=998244353;
const ll inf=INF*INF;
const ll mod=INF;
const ll MAX=200010;
const double PI=acos(-1.0);
typedef vector<vector<ll> > mat;
typedef vector<ll> vec;

ll dx[]={0,1,0,-1};
ll dy[]={1,0,-1,0};

void solve(){
    ll N,V,C;cin>>N>>V>>C;
    vector<vector<ll> >dp(N+1,vector<ll>(V+1));
    vector<ll>v(N),w(N);
    rep(i,N)cin>>v[i]>>w[i];
    rep(i,N+1){
        if(i>0){
            rep(j,V+1){
                if(j-v[i-1]>=0)dp[i][j]=max(dp[i][j],dp[i][j-v[i-1]]+w[i-1]);
            }
        }
        if(i<N){
            rep(j,V+1){
                dp[i+1][j]=max(dp[i+1][j],dp[i][j]);
                if(j+v[i]<=V)dp[i+1][j+v[i]]=max(dp[i+1][j+v[i]],dp[i][j]+w[i]+C);
            }
        }
    }
    ll ans=0;
    rep(i,V+1)ans=max(ans,dp[N][i]);
    cout<<ans<<endl;
}

signed main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    solve();
}