#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<ll,ll>;
#define fix(x) fixed << setprecision(x)
#define asc(x) x, vector<x>, greater<x>
#define rep(i, n) for(ll i = 0; i < n; i++)
#define all(x) (x).begin(),(x).end()
template<class T>bool chmin(T&a, const T&b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool chmax(T&a, const T&b){if(a<b){a=b;return 1;}return 0;}

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int n,v,c,ans = 0;
    cin >> n >> v >> c;
    vector<int> dp(v+1, -1), dp2(v+1, -1);
    dp[0] = dp2[0] = 0;
    rep(i,n){
        int x,y;
        cin >> x >> y;
        rep(j,v){
            if(j+x>v) break;
            if(dp[j]>=0)  chmax(dp2[j+x], dp[j]+y+c);
            if(dp2[j]>=0) chmax(dp2[j+x], dp2[j]+y);
            chmax(ans,dp2[j+x]);
        }
        dp = dp2;
    }
    cout << ans << '\n';
    return 0;
}