#include<cstdio>

#include<cstring>

#include<algorithm>

using namespace std;

const int maxn=,maxm=;

int a[maxm],b[maxn],f[maxn],l,s,t,n;

int main()

{

    scanf("%d%d%d%d",&l,&s,&t,&n);

    for(int i=;i<=n;i++)scanf("%d",&a[i]);

    int ans=;

    if(s==t)

     {

         for(int i=;i<=n;i++)if(a[i]%s==)ans++;

         printf("%d",ans);

         return ;

     }

    sort(a,a+n+);

    int ago=,mark=,p=t*(t-)+;

    for(int i=;i<=n;i++)

     {

         if(a[i]-ago>=p)

          b[(mark+=p)]=;

         else b[(mark=mark+a[i]-ago)]=;

        ago=a[i];

     }

    if(l-ago>p)

     mark+=p;

    else mark=mark+l-ago;

    memset(f,0x3f,sizeof(f));

    f[]=;

    for(int i=s;i<=mark;i++)

     for(int j=s;j<=t;j++)

      {

          f[i]=min(f[i],f[i-j]+b[i]);

      }

/*    for(int i=0;i<=mark;i++)printf("%d ",i);printf("\n");

    for(int i=0;i<=mark;i++)printf("%d ",b[i]);printf("\n");

    for(int i=0;i<=mark;i++)if(f[i]>1000)printf("x ");else printf("%d ",f[i]);*/

    printf("%d",f[mark]);

    return ;

}