/**
 *   @FileName	a.cpp
 *   @Author	kanpurin
 *   @Created	2022.05.20 22:54:56
**/

#include "bits/stdc++.h" 
using namespace std; 
typedef long long ll;


int main() {
    int n,V,C;cin >> n >> V >> C;
    vector<vector<ll>> dp(V+1,vector<ll>(2));
    ll ans = 0;
    for (int i = 0; i < n; i++) {
        int v,w;cin >> v >> w;
        for (int j = 0; j <= V; j++) {
            dp[j][0] = max(dp[j][0],dp[j][1]);
            if (j>=v) dp[j][1] = max(dp[j-v][0]+C+w,dp[j-v][1]+w);
            ans = max(dp[j][0],dp[j][1]);
        }
    }
    cout << ans << endl;
    return 0;
}