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

void chmax(int& x, const int y) {
	x = max(x, y);
}

#define rep(i, x) for(int i = 0; i < (x); i++)

using T = tuple<int, int, int>;
int n, K, x, y, res;
int main() {
	cin >> n >> K >> x >> y;
	x %= K, y %= K;
	vector a(n, 0);
	vector dp(vector(K, vector(K, -1)));
	vector dp2(vector(K, -1));
	for(auto& v : a) cin >> v, v %= K;

	dp[x][y] = 0;
	dp2[x] = dp2[y] = 0;

	rep(i, n) {
		queue<T> upd;
		rep(j, K) {
			for(int sum = 0; sum <= 2 * K; sum += K) {
				int k = sum - j - a[i];
				if(!(clamp(k, 0, K - 1) == k)) continue;
				auto& now = dp[j][k];
				if(now == -1) continue;
				upd.emplace(j, k, now + 1);
				upd.emplace(a[i], j, now + 1);
				upd.emplace(a[i], k, now + 1);
			}
			upd.emplace(j, a[i], dp2[j]);
		}
		while(!upd.empty()) {
			auto [j, k, val] = upd.front();
			upd.pop();
			chmax(dp[j][k], val);
			chmax(dp[k][j], val);
			chmax(dp2[j], val);
			chmax(dp2[k], val);
		}
	}

	rep(i, K) chmax(res, *max_element(dp[i].begin(), dp[i].end()));

	cout << res << '\n';

	return 0;
}