#include <stdio.h>
#include <vector>
using namespace std;

int n, a, b, k;
long long cnt;
vector<int> d;
vector<long long> sum;

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

        if(i - b > 0)
            d[sum[i-b-1]]--;

        cnt += d[sum[i]];
    }
    printf("%lld",cnt);
    return 0;
}