#include <stdlib.h>
#include <stdio.h>

typedef struct {
  int h;
  int g;
}gutui;

int compareG(const void *a, const void *b) 
{
    gutui *aa = (gutui *)a;
    gutui *bb = (gutui *)b;
    return (bb->g -aa->g);
}
 int retrieve(int test[],int index,int h_max,int u,gutui *a)
{   
     for(;index>=0;index--)
            if(test[index]==0)
            {
                       test[index]=1;
                       return 1;
            }  
          /*  if(test[index]>0) 
              for(index;index>=0;index--) 
                if(test[index]==0) //daca mai pot lua gutui
            {
                       test[index]=1;
                       return 1;
            } */
             
   return 0;
}
int main()
{
    FILE *fis=fopen("gutui.in","r");
    FILE *fis_out=fopen("gutui.out","w");
    int n,h_max,u,i,j,aux=0,greutate=0,ok=0;
    fscanf(fis,"%i",&n);
    gutui a[n];
    fscanf(fis,"%i",&h_max);
    fscanf(fis,"%i",&u);
    for(i = 0; i < n; i++)
        fscanf(fis, "%i %i", &a[i].h,&a[i].g);
    qsort(a,n,sizeof(gutui),compareG);    //gutui sortate descrescator dupa greutate
    int test[h_max/u+1];
     for(i=0;i<=h_max/u;i++)
           test[i]=0;
 for(i=0;i<n;i++)
   a[i].h=1 +(h_max-a[i].h)/u; 
     for(i=0;i<n;i++)
         if(retrieve(test,a[i].h,h_max,u,a)==1)
                  greutate+=a[i].g;
       printf("Greutate max: %i",greutate);
  fprintf(fis_out,"%i",greutate);
 //getch();
   return 0; 
}