#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
const int maxn=1000+5;
int dp[maxn][30+5];
int s[maxn];
int ans=-1,cnt=1,n,m;
int A,B,C;
int main()
{
	scanf("%d%d",&n,&m);
	for(int i=1,p,q;i<=n;i++){
		scanf("%d",&p);
		if(i==1)	{s[cnt++]=i;A=p-1;q=p;}
		else if(p!=q)	{s[cnt++]=i;q=p;}
	}
	s[cnt]=n+1;
	memset(dp,-1,sizeof(dp));
	dp[0][0]=0;
	for(int i=1;i<=cnt;i++){
		for(int j=0;j<=m&&j<=i;j++){
			C=i%2?A:1-A;
			B=j%2;
			int tmp=j?(dp[i-1][j]==-1?dp[i-1][j-1]:max(dp[i-1][j],dp[i-1][j-1])):dp[i-1][j];
			dp[i][j]=tmp+(B==C?s[i+1]-s[i]:0);
		}
	}
	for(int i=0;i<=m&&i<=cnt;i++)	if(ans<dp[cnt][i])	ans=dp[cnt][i];
	printf("%d\n",ans);
	return 0;
}