#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<vector>
#include<queue>
#include<functional>
#include<utility>
#include<cassert>
using namespace std;
inline long long read(){
    long long x = 0,f = 1;
    char c = getchar();
    while(c < '0' || c > '9'){
        if(c == '-') f = -1;
        c = getchar();
    }
    while(c >= '0' && c <= '9'){
        x = (x << 3) + (x << 1) + (c ^ 48);
        c = getchar();
    }
    return x * f;
}
const int N = 5011;
int n,w,k;
long long val[N],res,f[N][N << 1];
struct yjx{
    long long w,v;
}a[N];
bool cmp(yjx x,yjx y){
    return x.w < y.w;
}
priority_queue<long long,vector<long long>,greater<long long> > P;
int main(){
    int t,i,j,k,x,y,s;
    n = read(),w = read(),k = read();
    for(i = 1;i <= n;i++) a[i].w = read(),a[i].v = read();
    sort(a + 1,a + n + 1,cmp);
    for(i = 1;i <= n;i++){
        for(j = w;j >= a[i].w;j--){
            f[i][j] = max(f[i - 1][j],f[i - 1][j - a[i].w] + a[i].v);
            val[i] = max(val[i],f[i][j]);
        }
    }
    long long sum = 0;
    for(i = n;i >= 1;i--){ 
        if((int)P.size() < k) P.push(a[i].v),sum += a[i].v;
        else{
            if(a[i].v > P.top()){
                sum += a[i].v - P.top();
                P.pop();
                P.push(a[i].v);
            }
        }
        res = max(res,val[i - 1] + sum);
    }
    printf("%lld\n",res);
    return 0;
}