#include <fstream>
using namespace std;
ifstream fin("divk.in");
ofstream fout("divk.out");
#define nmax 500001
int dp[nmax], sum[nmax], k, n, a, b;
int main()
{
    int i;
    unsigned long long sol=0;
    fin>>n>>k>>a>>b;
    for(i=1; i<=n; i++)
    {
        fin>>sum[i];
        sum[i]=(sum[i-1]+sum[i])%k;
    }
    for(i=a; i<=n; i++)
    {
        dp[sum[i-a]]++;
        if(i>b)
            dp[sum[i-b-1]]--;
        sol+=dp[sum[i]];
    }
    fout<<sol;
    return 0;
}