#include <iostream>
#include <algorithm>
using namespace std;
const int nmax=100000*4+5;
int n,j,i;
struct sir {int ini,val;};
sir a[nmax];
int dp[nmax];
int poz[nmax];

bool cmp (sir A , sir B)
{
    return A.val<B.val;
}

int main()
{
   cin>>n;
   for (i=1;i<=n;i++)
   {
      cin>>a[i].val;
      a[i].ini=i;
      if (a[i].val%n==0)
      {
          cout<<"1"<<'\n';
          cout<<i;
          return 0;
      }
   }

   for (i=1;i<=n;i++)
    dp[i]=a[i].val+dp[i-1];

   for (i=1;i<=n;i++)
   {
     dp[i]%=n;
     if (dp[i]==0)
     {
         cout<<i<<'\n';
         for (j=1;j<=i;j++)
            cout<<j<<" ";
        return 0;
     }
   }

   for (i=1;i<=n;i++)
   {
        if (poz[dp[i]]!=0)
        {
           cout<<i-poz[dp[i]]<<'\n';
           for (j=poz[dp[i]]+1;j<=i;j++)
            cout<<a[j].ini<<" ";
           return 0;
        }
        else
            poz[dp[i]]=i;
   }

   sort (a+1,a+n+1,cmp);
   for (i=1;i<=n;i++)
   {
       poz[i]=0;
       dp[i]=a[i].val+dp[i-1];
   }

   for (i=1;i<=n;i++)
    dp[i]=a[i].val+dp[i-1];

   for (i=1;i<=n;i++)
   {
     dp[i]%=n;
     if (dp[i]==0)
     {
         cout<<i<<'\n';
         for (j=1;j<=i;j++)
            cout<<a[j].ini<<" ";
        return 0;
     }
   }

   for (i=1;i<=n;i++)
   {
        if (poz[dp[i]]!=0)
        {
           cout<<i-poz[dp[i]]<<'\n';
           for (j=poz[dp[i]]+1;j<=i;j++)
            cout<<a[j].ini<<" ";
           return 0;
        }
        else
            poz[dp[i]]=i;
   }
}