#include <bits/stdc++.h>
long long mod = 1e9;
long long MOD = 1e18;
using namespace std;
bool comp(const pair<int, int>& p, const pair<int, int>& q) {
  return (p.first < q.first);
}
bool comp2(const pair<int, int>& p, const pair<int, int>& q) {
  if (p.second != q.second) return (p.second < q.second);
  return (p.first < q.first);
}
long long pp(long long a, long long b) {
  long long t = 1;
  while (b) {
    if (b & 1) t = (t * a) % mod;
    a = (a * a) % mod;
    b /= 2;
  }
  return t;
}
bool isprime(int n) {
  int i = 2;
  if (n == 1) return true;
  if (n == 2) return true;
  for (; i * i <= n; i++) {
    if (n % i == 0) return false;
  }
  return true;
}
long long lcd(long long n, long long m) {
  if (n > m) swap(m, n);
  if (m % n == 0)
    return m;
  else {
    int p = n + n;
    while (1) {
      if (p % m == 0)
        return p;
      else
        p = (n + p) % MOD;
    }
  }
}
int main() {
  int n, k;
  cin >> n >> k;
  int a[n], i, cnt = 1, mx = 0;
  for (i = 0; i < n; i++) cin >> a[i];
  for (i = 1; i < n; i++) {
    if (a[i] != a[i - 1])
      cnt++;
    else {
      mx = max(cnt, mx);
      cnt = 1;
    }
  }
  mx = max(cnt, mx);
  cout << mx;
}
