#include <cstdio>
#define MAXN 1000000
int time[MAXN+1];
int main(){
   FILE*fi,*fout;
   int i,j,d,n,k,last,ans;
   fi=fopen("zombie.in" ,"r");
   fout=fopen("zombie.out" ,"w");
   fscanf(fi,"%d %d %d " ,&d,&n,&k);
   for(i=1;i<=n;i++)
     fscanf(fi,"%d " ,&time[i]);
   i=1;
   ans=0;
   while(i<=n){
       last=time[i]+d-1;
       j=i;
       while(j<=n&&time[j]<=last)
         j++;
       if(j-i>k)
         ans+=k;
       else
         ans+=j-i;
       i=j;
   }
   fprintf(fout,"%d" ,ans);
   fclose(fi);
   fclose(fout);
   return 0;
}