http://acm.hdu.edu.cn/showproblem.php?pid=1709
//1306899 2009-04-25 09:13:59 Accepted 1709 78MS 336K 805 B C++ no way 
#include<iostream>
#include<cmath>
using namespace std;
int main()
{
    int n;
    while(cin>>n && n>0)
    {
        int i,j,k,N=0;
        int w[101],temp[10001],outs[10001];
        for(i=1;i<=n;i++)
        {
            scanf("%d",&w[i]);
            N += w[i];
        }
        for(i=0;i<=N;i++)
            temp[i] = outs[i] = 0;
        outs[0] = 1;
        outs[w[1]] = 1;
        for(i=2;i<=n;i++)
        {
            for(j=0;j<=N;j++)
            {
                if(outs[j] == 1)
                {
                    temp[j] = 1;//標志j出現過
                    temp[j+w[i]] = 1;//加一個
                    temp[abs(j-w[i])] = 1;//減一個
                }
            }
            for(j=0;j<=N;j++)
            {
                outs[j] = temp[j];
                temp[j] = 0;
            }
        }
        k = 0;
        for(i=1;i<=N;i++)
            if(outs[i] == 0)
                temp[k++] = i;
        printf("%d\n",k);
        if(k>0)
        {
            printf("%d",temp[0]);
            for(i=1;i<k;i++)
                 printf(" %d",temp[i]);
            printf("\n");
        }
    }
    return 0;
}