#include <cstdio>

using namespace std;

int v[500010],v1[100010];

int main()
{
    freopen("divk.in","r",stdin);
    freopen("divk.out","w",stdout);
    int n,k,a,b;
    long long sol=0;
    scanf("%d%d%d%d",&n,&k,&a,&b);
    for(int i=1;i<=n;i++)
    {
        scanf("%d",&v[i]);
        v[i]=(v[i-1]+v[i])%k;
    }
    for(int i=0;i<=n-a;i++)
    {
        if(i>0) v1[v[i]]++;
        if(i-(b-a)-1>0) v1[v[i-(b-a)-1]]--;
        sol+=v1[v[i+a]];
        if(v[i+a]==0 && i+a<=b) sol++;
    }
    printf("%lld",sol);
    return 0;
}