#include <bits/stdc++.h>

using namespace std;
using ll = long long;

int main(){

    ll N, V, C;
    cin >> N >> V >> C;
    vector<ll> v(N+1), w(N+1);
    vector<vector<vector<ll>>> dp(N+1, vector(V+1, vector<ll>(2)));
    for (int i=1; i<=N; i++) cin >> v[i] >> w[i];

    for (int i=1; i<=N; i++){
        for (int j=0; j<=V; j++){
            dp[i][j][0] = max({dp[i][j][0], dp[i-1][j][0], dp[i-1][j][1]});
            if (j-v[i] >= 0) dp[i][j][1] = max({dp[i][j][1], dp[i][j-v[i]][0]+w[i]+C, dp[i][j-v[i]][1]+w[i]});
        }
    }

    cout << max(dp[N][V][0], dp[N][V][1]) << endl;

    return 0;
}