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

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

int compareG(const void *a, const void *b) 
{
    gutui *aa = (gutui *)a;
    gutui *bb = (gutui *)b;
    return ((*bb).g -(*aa).g);
}
int main()
{
    FILE *fis=fopen("gutui.in","r");
    FILE *fis_out=fopen("gutui.out","w");
    int n,h_max,u,i,max=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
  
 for(i=0;i<n;i++)
   { a[i].level=1+(h_max-a[i].h)/u; 
      if (a[i].level>max)
         max=a[i].level;
      }
 int test[max+1];
     for(i=0;i<=max;i++)
           test[i]=0;
     for(i=0;i<n;i++)
     {
      int ok=0;
      if(test[a[i].level]==0 && ok==0)
            {
                       test[a[i].level]=1;
                       greutate+=a[i].g;
                       ok=1;
            } 
           else 
              for(a[i].level;a[i].level>0;a[i].level--) 
                if(test[a[i].level]==0 && ok==0) 
            {
                       test[a[i].level]=1;
                       greutate+=a[i].g;
                       ok=1;
            }              
    }
  printf("Greutate max: %i",greutate);
  fprintf(fis_out,"%i",greutate);
// getch();
   return 0; 
}