#include <bits/stdc++.h>
#define maxN 1002
#define maxT 50002
#define ll long long
using namespace std;

FILE *fin = freopen("peste.in", "r", stdin);
FILE *fout = freopen("peste.out", "w", stdout);

/* ==================== */
int n, k, totalT;
/* ==================== */
struct Net
{
    int f, t;
    bool operator < (const Net &ot) const
    {
        if (t == ot.t)
            return f < ot.f;
        return t < ot.t;
    }
} v[maxN];
priority_queue < int > q;

ll dp[maxT], best[maxT];

/* ==================== */
ll ans;

void compBest()
{
    ll sum = 0;
    for (int i = 1; i <= n; ++ i)
    {
        sum += 1LL * v[i].f;
        q.push(-v[i].f);
        if (i > k)
        {
            sum += q.top();
            q.pop();
        }
        best[v[i].t] = max(best[v[i].t], sum);
    }
    for (int i = 1; i < maxT; ++ i)
        best[i] = max(best[i], best[i - 1]);
}


int main()
{
    scanf("%d %d %d", &n, &k, &totalT);
    for (int i = 1; i <= n; ++ i)
        scanf("%d %d", &v[i].f, &v[i].t);

    sort(v + 1, v + n + 1);
    compBest();
    for (int i = 1; i <= totalT; ++ i)
    {
        dp[i] = max(dp[i], dp[i - 1]);
        for (int j = 1; j <= i; ++ j)
            dp[i] = max(dp[i], best[j] + dp[i - j]);
    }
    printf("%lld\n", dp[totalT]);

    return 0;
}