学步园

#include<stdio.h>

int main()
{
    double sum;
    int k,n;
    while(scanf("%d",&n)==1&&n)
    {
        k=0;
        sum=(n+1)*1.0*n/6.0*(n+2);//必须用n/6.0才能过
            while(sum>=10)
            {
                sum/=10.0;k++;
            }

        printf("%.2lfE%d\n",sum,k);
    }
    return 0;
}