/*

* File: main.cpp

* Author: Administrator

*

* Created on 2010年7月8日, 上午1:15

*/

/**/

#include <cstdlib>

#include <iostream>

#define mm 110000

#define min(a,b) (a)<(b)?(a):(b)

#define max(a,b) (a)>(b)?(a):(b)

using namespace std;

int main(int argc, char** argv) {

long *a=new long[mm];

long *f=new long[mm];

long n,q;

long t,ans=0;

cin >>n>>q;

for (long i=1;i<=n;i++) cin >>a[i];

for (long i=n;i>=1;i--){

t=100000;

for (int j=1;j<=q;j++) t=min(f[j],t);

f[a[i]]=t+1;

ans=max(ans,f[a[i]]);

}

cout <<ans<<endl;

return 0;

}