#include <bits/stdc++.h>
using namespace std;

ifstream fin("divk.in");
ofstream fout("divk.out");

#define NMAX 500005

int n,k,a,b;
int v[NMAX];
int sum[NMAX];
int first[100005];
int last[100005];


int main()
{
    fin>>n>>k>>a>>b;
    for(int i=1;i<=n;i++)
    {
        fin>>v[i];
        v[i] = v[i] % k;
    }

    for(int i=1;i<=n;i++)
    {
        sum[i] = (sum[i-1] % k + v[i] % k) % k;
    }

    for(int i=1;i<=n;i++)
    {
        if(!first[sum[i]])
            first[sum[i]] = i;
        last[sum[i]] = i;
    }

    int maxim = 0;
    for(int i=0;i<=100000;i++)
    {
        int lg = last[i] - first[i] + 1;
        if(lg >= a && lg <= b && lg > maxim)
            maxim = lg;
    }
    fout<<maxim;

    return 0;
}