#include"iostream"

#include"algorithm"

#include"cstring"

using namespace std;

const int maxn=;

int dp[maxn],ok[maxn],ans[maxn];

int main()

{

    int sum,n,temp;

    while(cin>>n)

    {

        memset(dp,,sizeof(dp));

        dp[]=;

        sum=;

        for(int i=;i<=n;i++)

        {

            cin>>temp;

            memset(ok,,sizeof(ok));

            sum+=temp;

            for(int j=;j<=sum;j++) if(dp[j])

            {

                ok[j+temp]=;

                ok[abs(j-temp)]=;

            }

            for(int j=;j<=sum;j++) if(ok[j])

            dp[j]=;

        }

        int top=;

        for(int i=;i<=sum;i++)

        {

            if(dp[i]==) ans[top++]=i;

        }

        cout<<top<<endl;

        if(top)

        {

        for(int j=;j<top-;j++) cout<<ans[j]<<" ";

        cout<<ans[top-]<<endl;

        }

    }

    return ;

}