#include<stdio.h>
int N,M,K;
char b[1002020];
int v[1020200],x,S,st,dr;//brut :D

int main()
{
    freopen("pod.in","r",stdin);
    freopen("pod.out","w",stdout);

    scanf("%d%d%d",&N,&M,&K);
    if(N<1020030)
    {


    for(int i=1;i<=M;++i)
        {
        scanf("%d",&x);
        b[x]=1;
        }

    v[0]=1;
    for(int i=0;i<=N;++i)
    {
    if(b[i+1]!=1)
    v[i+1]+=v[i];
    if(b[i+K]!=1)
    v[i+K]+=v[i];
    }

    printf("%d\n",v[N]);
    }
    else printf("0\n");
}