#include<stdio.h>
#define N 500001
long c,n,k,a,b,i,j,t;
long long s[N],l=0;
int main()
{freopen("divk.in","r",stdin);
freopen("divk.out","w",stdout);
scanf("%ld%ld%ld%ld\n",&n,&k,&a,&b);
s[0]=0;
for(i=1;i<=n;i++)
       {scanf("%ld\n",&c);
       s[i]=s[i-1]+c;}
t=0;
j=a;
while(t+j<=n)
       {s[j]=s[j+t]-s[t];
       if(s[j]%k==0)
              l++;
       if(j<b)
              j++;
       else
              {j=a;
              t++;}}
printf("%lld\n",l);
fclose(stdin);
fclose(stdout);
return 0;}