#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;}
//-------------------------------------------------------

template<class V,int NV> class SegTree_1 {
public:
	vector<V> val;
	static V const def=-(1<<20);
	V comp(V l,V r){ return max(l,r);};
	
	SegTree_1(){val=vector<V>(NV*2,def);};
	V getval(int x,int y,int l=0,int r=NV,int k=1) { // x<=i<y
		if(r<=x || y<=l) return def;
		if(x<=l && r<=y) return val[k];
		return comp(getval(x,y,l,(l+r)/2,k*2),getval(x,y,(l+r)/2,r,k*2+1));
	}
	void update(int entry, V v) {
		entry += NV;
		val[entry]=comp(v,val[entry]); //上書きかチェック
		while(entry>1) entry>>=1, val[entry]=comp(val[entry*2],val[entry*2+1]);
	}
};
SegTree_1<int,1<<11> 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].update(x,v);
		C[x].update(y,v);
	}
}


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