> #include <stdio.h>
> #include <string.h>
> #define Min(a,b) ((a)<(b))?(a):(b)
> int main()
> {
> 	int dp[31],n,m,i,j,x;
> 	while(scanf("%d%d",&n,&m)!=EOF)
> 	{
> 		memset(dp,0,sizeof(dp));
> 		for(i=1;i<=n;i++)
> 		{
> 			scanf("%d",&x);
> 			x--;
> 			for(j=Min(m,i);j>=0;j--)
> 			{
> 				if(x==j%2)
> 					dp[j]++;
> 				else if(j-1>=0 && dp[j-1]+1>dp[j])
> 					dp[j]=dp[j-1]+1;
> 			}
> 		}
> 		printf("%d\n",dp[m]);
> 	}
> 	return 0;
> }