#include "stdio.h"
#include "math.h"

int main(){
	long it;
	int i,j,max,offer,temp;
	for(scanf("%d",&offer);offer!=0;scanf("%d",&offer),max=0){
		for (i=0;(it=i*i*i)<=offer;i++){
			for (j=(int)pow(6*(offer-it),1/3.0)+2;(temp=it+j*(j+1)*(j+2)/6)>offer;j--);
			max=temp>max?temp:max;
		}
		printf("%d\n",max);
	}
	return 0;
}