#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
//const int INF = 1e9;
//const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
long long dp[5001][5001];
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n, v, c;
	cin >> n >> v >> c;
	vector<int>a(n), b(n);
	rep(i, n)cin >> a[i] >> b[i];
	rep(i, n) {
		int ni = i + 1;
		rep(j, v + 1) {
			chmax(dp[ni][j], dp[i][j]);
			int nj = j + a[i];//cost
			if (nj > v)continue;
			int val = dp[i][j] + b[i] + c;//value
			chmax(dp[ni][nj], val);
		}
		rep(j, v + 1) {
			int nj = j + a[i];
			if (nj > v)continue;
			int val = dp[ni][j] + b[i];
			chmax(dp[ni][nj], val);
		}
		//rep(j, v + 1) cout << dp[i+1][j] << " ";
		//cout << endl;
	}
	long long ans = 0;
	rep(i, v + 1)chmax(ans, dp[n][i]);
	cout << ans << endl;
	return 0;
}