#include <bits/stdc++.h>
using namespace std;
ofstream fout("peste.out");
class InParser {
private:
    FILE *fin;
    char *buff;
    int sp;

    char read_ch() {
        ++sp;
        if (sp == 4096) {
            sp = 0;
            fread(buff, 1, 4096, fin);
        }
        return buff[sp];
    }

public:
    InParser(const char* nume) {
        fin = fopen(nume, "r");
        buff = new char[4096]();
        sp = 4095;
    }

    InParser& operator >> (int &n) {
        char c;
        while (!isdigit(c = read_ch()) && c != '-');
        int sgn = 1;
        if (c == '-') {
            n = 0;
            sgn = -1;
        } else {
            n = c - '0';
        }
        while (isdigit(c = read_ch())) {
            n = 10 * n + c - '0';
        }
        n *= sgn;
        return *this;
    }

    InParser& operator >> (long long &n) {
        char c;
        n = 0;
        while (!isdigit(c = read_ch()) && c != '-');
        long long sgn = 1;
        if (c == '-') {
            n = 0;
            sgn = -1;
        } else {
            n = c - '0';
        }
        while (isdigit(c = read_ch())) {
            n = 10 * n + c - '0';
        }
        n *= sgn;
        return *this;
    }
};
struct obiect
{
    int val, gr;
} o[50002];
struct plasa
{
    int p, t;
} v[50002];
priority_queue <int, vector <int>, greater <int> > que;
int n, k, nrob, ttotal;
long long best[50002];
bool d[1002];
inline bool cmp(const plasa a, const plasa b)
{
    return a.t<b.t;
}
int main()
{
    InParser fin("peste.in");
    int i, j, kk, sp=0;
    fin>>n>>k>>ttotal;
    for(i=1; i<=n; i++)
    {
        fin>>v[i].p>>v[i].t;
        d[v[i].t]=1;
    }
    sort(v+1,v+n+1,cmp);
    for(i=1; i<=n; i++)
    {
        while(v[i].t==v[i+1].t)
        {
            sp+=v[i].p;
            que.push(v[i].p);
            i++;
        }
        sp+=v[i].p;
        que.push(v[i].p);
        nrob++;
        o[nrob].gr=v[i].t;
        while(que.size()>k)
        {
            sp-=que.top();
            que.pop();
        }
        o[nrob].val=sp;
    }
    for(i=1; i<=ttotal; i++)
        for(j=1; j<=nrob && o[j].gr<=i; j++)
            best[i]=max(max(best[i],best[i-o[j].gr]+(long long)o[j].val),best[i-1]);
    fout<<best[ttotal]<<'\n';
    return 0;
}