#include<bits/stdc++.h>
using namespace std;
ifstream I("economie.in");
ofstream O("economie.out");
int n,i,k,j,v[1001],h[1001],f[50001];
int main()
{
    I>>n;
    for(i=1;i<=n;++i)
        I>>v[i];
    sort(v+1,v+n+1),f[0]=1;
    for(i=1;i<=n;++i) {
        if(!f[v[i]])
            h[++k]=v[i];
        for(j=0;j+v[i]<=v[n];++j)
            if(f[j]==1)
                f[j+v[i]]=1;
    }
    O<<k<<"\n";
    for(i=1;i<=k;++i)
        O<<h[i]<<" ";
    return 0;
}