#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k, i;
  int rs = 1;
  int temp_rs = 1;
  cin >> n >> k;
  int mang[n];
  for (i = 0; i < n; i++) {
    cin >> mang[i];
    if (i > 0) {
      if (mang[i] != mang[i - 1]) {
        rs += 1;
      } else {
        rs = 1;
      }
      if (rs > temp_rs) {
        temp_rs = rs;
      }
    }
  }
  cout << temp_rs;
  return 0;
}
