#include <fstream>
#include <vector>
#include <cstring>
#include <algorithm>
#include <queue>

const int kMaxDim = 50005;

struct Net {
	Net(int _fish = 0, int _time = 0) :
		fish(_fish),
		time(_time) {
	}

	bool operator < (const Net& obj) const {
		return this->time < obj.time;
	}

	int fish, time;
};

int netCount, maximumNets, totalTime;
long long precalcMaximumFishCount[kMaxDim], dp[kMaxDim];
Net nets[kMaxDim];

std::priority_queue< int > heap;

int main() {
	std::ifstream inputFile("peste.in");
	std::ofstream outputFile("peste.out");

	inputFile >> netCount >> maximumNets >> totalTime;
	for (int i = 0; i < netCount; ++i)
		inputFile >> nets[i].fish >> nets[i].time;

	std::sort(nets, nets + netCount);

	for (int i = 0, sum = 0; i < netCount; ++i) {
		heap.push(-nets[i].fish);
		sum += nets[i].fish;

		while ((int)heap.size() > maximumNets) {
			sum += heap.top();
			heap.pop();
		}

		precalcMaximumFishCount[nets[i].time] = sum;
	}

	for (int i = 1; i <= nets[netCount - 1].time; ++i)
		precalcMaximumFishCount[i] = std::max(precalcMaximumFishCount[i], precalcMaximumFishCount[i - 1]);

	for (int i = 1; i <= totalTime; ++i)
		for (int j = 1; j <= i && j <= nets[netCount - 1].time; ++j)
			dp[i] = std::max(dp[i], dp[i - j] + precalcMaximumFishCount[j]);

	outputFile << dp[totalTime] << '\n';

	inputFile.close();
	outputFile.close();

	return 0;
}

//Trust me, I'm the Doctor!