#include <algorithm>
#include <stdio.h>
#include <set>

#define MAX 50010
#define ll long long
#define mp make_pair
#define timp first
#define peste second

using namespace std;

ll n, k, timp, tMax;
pair <ll, ll> p[MAX];
ll sol[MAX], prins[MAX];
multiset <ll> setPlase;

int main()
{
	freopen("peste.in", "r", stdin);
	freopen("peste.out", "w", stdout);

	scanf("%d %d %d", &n, &k, &timp);

	for (int i = 1; i <= n; i++)
	{
		scanf("%lld %lld", &p[i].peste, &p[i].timp);
		tMax = max(tMax, p[i].timp);
	}

	sort(p + 1, p + 1 + n);

	int sum = 0, r = 1;
	for (int i = 1; i <= tMax; i++)
	{
		for (; r <= n && p[r].timp <= i; sum += p[r].peste, setPlase.insert(p[r].peste), r++);
		for (; setPlase.size() > k; sum -= (*setPlase.begin()), setPlase.erase(setPlase.begin()));

		prins[i] = sum;
	}

	for (int i = 1; i <= timp; i++)
		for (int j = 1; j <= min(i, (int) tMax); j++)
			sol[i] = max(sol[i], sol[i - j] + prins[j]);

	printf("%lld\n", sol[timp]);

	fclose(stdin);
	fclose(stdout);
	return 0;
}