> #include<stdio.h>
> #define in(a,b) (a<b?a:b)
> int n,m;
> int minv[21],mins[21];
> int bests;
> 
> void dfs(int v,int s,int level,int r,int h)
> {
> 	if(level==0)
> 	{
> 		if(v==n && s<bests)
> 			bests=s;
> 		return ;
> 	}
> 	if(v+minv[level-1]>n || s+mins[level-1]>bests || 2*(n-v)/r+s>=bests)                //如果把中括号内的level-1都换成level就是32ms
> 		return ;
> 	int i,j,hh;
> 	for(i=r-1;i>=level;i--)
> 	{
> 		if(level==m)
> 			s=i*i;
> 		hh=in((n-v-minv[level-1])/(i*i),h-1);
> 		for(j=hh;j>=level;j--)
> 			dfs(v+i*i*j,s+2*i*j,level-1,i,j);
> 	}
> 			
> }
> 
> int main()
> {
> 	int i;
> 	minv[0]=0;
> 	mins[0]=0;
> 	for(i=1;i<=20;i++)
> 	{
> 		minv[i]=minv[i-1]+i*i*i;
> 		mins[i]=mins[i-1]+2*i*i;
> 	}
> 	while(scanf("%d%d",&n,&m)==2)
> 	{
> 		bests=0x7fffffff;
> 		dfs(0,0,m,n+1,n+1);
> 		if(bests==0x7fffffff)
> 			printf("0\n");
> 		else
> 			printf("%d\n",bests);
> 	}
> 	return 0;
> }
>