#include<stdio.h>
typedef struct element
{
    int greutate;
    struct nod *urm;
}nod;

void afisare(nod *x)
{
    if(x==NULL)
    {
        printf("lista este vida \n");
        return;
    }
    while(x!=NULL)
    {
        printf("greutatea: %i ",x->greutate);
        x = x->urm;
    }
    printf("\n");
}

void inserare(nod **q,int g)
{
    nod *aux,*p;
    p=*q;
    aux=(nod*)malloc(sizeof(nod));
    aux->greutate=g;
    aux->urm=NULL;
    if(p==NULL)
    {
        *q=aux;
    }
    else if(p->greutate<=aux->greutate)
    {
        aux->urm=p;
        *q=aux;
    }
    else
    {
        while(p->urm!=NULL && p->greutate>aux->greutate)
        {
            p=p->urm;
        }
        aux->urm=p->urm;
        p->urm=aux;
    }
}
void sterge_prim(nod **q)
{
    nod *p;
    p=*q;
    *q=p->urm;
}

int caut_max(int N,int h[],int g[],int H,int U,int *p)
{
    int i;
    for(i=0;i<N;i++)
    {
        if((h[i]<=H+U)&&(h[i]>H)&&(g[i]>0))
        {
            *p=i;
            return g[i];
        }
    }
    return 0;
}

int main()
{
    int N,H,U,i,j,x,totalg=0,max,M,*h,*g,**gutui,H_curent=0,index=0;
    FILE * pFile = fopen("gutui.in","r");
    FILE * dFile = fopen("gutui.out","w");
    fscanf(pFile,"%i",&N);
    fscanf(pFile,"%i",&H);
    fscanf(pFile,"%i",&U);
    h=(int*)malloc(N*sizeof(int));
    g=(int*)malloc(N*sizeof(int));
    for(i=0;i<N;i++)
    {
        fscanf(pFile,"%i",&h[i]);
        fscanf(pFile,"%i",&g[i]);
    }
    nod *prim = NULL;
    M=H/U+(H%U!=0); //numarul de linii in matrice
    nod **vector_liste;
    vector_liste=(nod**)malloc(M*sizeof(nod*));
    for(i=0;i<M;i++)
    {
        vector_liste[i]=(nod*)malloc(sizeof(nod));
        vector_liste[i]->greutate=0;
        vector_liste[i]->urm=NULL;
    }
    i=0;
    while(H_curent<=H-U)
    {
        do
        {
            max=caut_max(N,h,g,H_curent,U,&x);
            if(max)
            {
                inserare(&vector_liste[i],max);
                g[x]=0;
            }
        }while(max);
        H_curent=H_curent+U;
        i++;
    }
    /*for(i=0;i<M;i++)
    {
        afisare(vector_liste[i]);
        printf("\n");
    }*/
    for(i=0;i<M;i++)
    {
        if((vector_liste[i]->greutate==0)&&(totalg==0))
        {
            continue;
        }
        if(prim==NULL || vector_liste[i]->greutate>=prim->greutate)
        {
            //printf("pun o gutuie de greutate: %i\n",vector_liste[i]->greutate);
            totalg=totalg+vector_liste[i]->greutate;
            vector_liste[i]=vector_liste[i]->urm;
        }
        else
        {
            //printf("pun o gutuie de greutate din coada: %i\n",prim->greutate);
            totalg=totalg+prim->greutate;
            sterge_prim(&prim);
        }
        while(vector_liste[i]->greutate!=0)
        {
            inserare(&prim,vector_liste[i]->greutate);
            vector_liste[i]=vector_liste[i]->urm;
        }
    }
    fprintf(dFile,"%i\n",totalg);
    //printf("total %i\n",totalg);
    fclose(pFile);
    fclose(dFile);
    return 0;
}