#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define FORR2(x,y,arr) for(auto& [x,y]:arr)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
template<class T> bool chmax(T &a, const T &b) { if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a, const T &b) { if(a>b){a=b;return 1;}return 0;}
//-------------------------------------------------------

int R[2020],C[2020];


int N,K,X,Y;
int A[2020];
int ma[2020][2020];

void update(int y,int x,int v) {
	if(ma[y][x]<v) {
		ma[y][x]=v;
		R[y]=max(R[y],v);
		C[x]=max(C[x],v);
	}
}


void solve() {
	int i,j,k,l,r,x,y; string s;
	
	FOR(x,2020) FOR(y,2020) ma[x][y]=-1<<20;
	FOR(x,2020) R[x]=C[x]=-1<<20;
	
	cin>>N>>K>>X>>Y;
	update(X%K,Y%K,0);
	
	
	FOR(i,N) {
		cin>>j;
		j%=K;
		vector<int> cu,ru;
		FOR(x,K) {
			y=(3*K-x-j)%K;
			cu.push_back(max(C[x],ma[x][y]+1));
		}
		FOR(y,K) {
			x=(3*K-j-y)%K;
			ru.push_back(max(R[y],ma[x][y]+1));
		}
		FOR(x,K) {
			y=(3*K-x-j)%K;
			update(x,y,ma[x][y]+1);
		}
		FOR(x,K) update(j,x,cu[x]);
		FOR(y,K) update(y,j,ru[y]);
	}
	int ret=0;
	FOR(x,K) FOR(y,K) ret=max(ret,ma[y][x]);
	cout<<ret<<endl;
	
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}