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

signed main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int n, k;
	cin >> n >> k;
	int a[n];
	for (int i = 0; i < n; ++i) {
		cin >> a[i];
	}
	map <int, int> mp;
	int l = 0, res = 0;
	for (int r = 0; r < n; ++r) {
		++mp[a[r]];
		while (mp[a[r]] > k) {
			++l;
			--mp[a[l]];
		}
		res = max(res, r - l + 1);
	}
	cout << res;
	return 0;
}