#include<stdio.h>
#define NMAX 500024
#define KMAX 100024
int S[NMAX],R[KMAX];
//Asta asa, ca sa nu invat pt testul de la mate:D
int main()
{
    freopen("divk.in","r",stdin);
    freopen("divk.out","w",stdout);
    
    int N,K,A,B;
    scanf("%d%d%d%d",&N,&K,&A,&B);
    
    int i,a1;
    long long solfin=0;
    for(i=1; i<=N; ++i){
    scanf("%d",&a1);
    S[i]=S[i-1]+a1;
    }
    for(i=A; i<=B; ++i)
    ++R[S[i]%K];
    solfin+=R[0];

    for(i=2; i+A<=N; ++i)
    {
             if( i+B<=N )
                 ++R[ S[i+B-1]%K ];
             --R[ S[i+A-2]%K ];
             
             solfin+=R[ S[i]%K ];
    }
    printf("%lld\n",solfin);         
    return 0;
}