#include <iostream>
#include <vector>
#include <algorithm>
#include <utility>
#include <set>
#include <map>
#include <queue>
using namespace std;
int main()
{
    int N, V, C;
    cin >> N >> V >> C;
    vector<int> v(N), w(N);
    for (int i = 0; i < N; i++)
        cin >> v[i] >> w[i];
    vector<vector<int>> dp(N + 1, vector<int>(V + 1, -1));
    dp[0][0] = 0;
    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j <= V; j++)
        {
            if (dp[i][j] == -1)
                continue;
            if (j + v[i] <= V)
            {
                dp[i + 1][j + v[i]] = max(dp[i + 1][j + v[i]], dp[i][j] + w[i] + C);
            }
        }
        for (int j = 0; j <= V; j++)
        {
            if (j + v[i] <= V)
            {
                dp[i + 1][j + v[i]] = max(dp[i + 1][j + v[i]], dp[i + 1][j] + w[i]);
            }
            dp[i + 1][j] = max(dp[i + 1][j], dp[i][j]);
        }
    }
    cout << *max_element(dp[N].begin(), dp[N].end()) << endl;
}