#include<cstdio>

using namespace std;

const int nmax=500005;

int sp[nmax],sol[100005];
long long rez;
int main()
{
    freopen("divk.in","r",stdin);
    freopen("divk.out","w",stdout);
    int n,a,b,k,i;
    scanf("%d%d%d%d",&n,&k,&a,&b);
    for(i=1;i<=n;++i)
    {
        scanf("%d",&sp[i]);
        sp[i]+=sp[i-1];
        sp[i]%=k;
        if(i-b>0)
            sol[sp[i-b-1]]--;
        if(i-a>=0)
            sol[sp[i-a]]++;
        rez+=1LL*sol[sp[i]];
    }
    printf("%lld",rez);
}