#include <bits/stdc++.h>
#include <atcoder/all>

using namespace std;

//#define DISABLE_PRINT

#if defined(ENABLE_PRINT) && !defined(DISABLE_PRINT)

#define P(...) fprintf(stderr, __VA_ARGS__)
#define P2(fmt) fprintf(stderr, fmt)
#define LP fprintf(stderr, "L: %d\n", __LINE__)

#else

#define P(...) ((void)0)
#define P2(fmt) ((void)0)
#define LP ((void)0)

#endif

#define rep(i, n) for(int i = 0; i < (int)(n); ++i)
#define ALL(x) x.begin(),x.end()

using ll = long long;
using ull = unsigned long long;

int main(int, const char**)
{
    int N, V, C; cin >> N >> V >> C;
    vector<int> v(N), w(N);
    rep(i, N) cin >> v[i] >> w[i];
    vector<int> dp(V + 1, -1);
    dp[0] = 0;
    rep(i, N) {
        vector<int> t(V + 1, -1);
        auto cost = v[i];
        auto p = w[i] + C;
        rep(j, V + 1) {
            if(dp[j] == -1) continue;
            t[j] = max(t[j], dp[j]);

            if(j + cost > V) continue;
            t[j + cost] = max(t[j], dp[j] + p);
        }
        swap(dp, t);
    }
    vector<vector<int>> dp2(N + 1, vector<int>(V + 1, 0));
    rep(i, V + 1) dp2[0][i] = dp[i] == -1 ? 0 : dp[i];
    rep(i, N) rep(j, V + 1) {
        if(j - v[i] < 0) {
            dp2[i + 1][j] = max(dp2[i + 1][j], dp2[i][j]);
        } else {
            dp2[i + 1][j] = max(dp2[i][j], dp2[i + 1][j - v[i]] + w[i]);
        }
    }

    int ans = 0;
    rep(i, V + 1) ans = max(ans, dp2[N][i]);
    cout << ans << endl;

    return 0;
}