#include <stdio.h>

using namespace std;
int v[500001],s[500001];

int main()
{
    int N , A , B , K , i = 0 , contor = 0 , i1  , s1;
    freopen("divk.in","r",stdin);
    freopen("divk.out","w",stdout);
    scanf("%d%d%d%d", &N , &K, &A, &B);
    s[1] = 0 ;s[0] = 0 ;
    for(i = 1 ; i <= N ; ++ i)
    {
        scanf("%d", &v[i]);
        s[i] = s[i - 1] + v[i];
    }
   /* for(i = 1 ; i <= N ; ++i)
    {
        for(i1 = A + i - 1 ; i1 <= B + i - 1 && i1 <= N ; ++i1)
        {
                s1 = s[i1] - s[i - 1];
                if(s1 % K == 0)
                    contor++;
        }
    }*/
    i = 1 ; i1 = A + i - 1;
    while(i <= N)
    {
        if(i1 <= B + i - 1 && i1 <= N)
        {
            s1 = s[i1] - s[i - 1];
            if(s1 % K == 0)
                contor++;
            i1++;
        }
        else
        {
            i++;
            i1 = A + i - 1 ;
        }
    }
     printf("%d", contor);

}