#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int n, k;
  cin >> n >> k;
  int a[n];
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  int ans = 0, count = 0;
  for (int i = 1; i < n; i++) {
    if (a[i] != a[i - 1])
      count++;
    else {
      ans = max(ans, count);
      count = 0;
    }
  }
  cout << max(ans + 1, count + 1);
  return 0;
}
