#include<bits/stdc++.h>
using namespace std;

int i,n,j,a[400005],poz[400005];
long long sum[400005];
map<long long,bool> M;

int main()
{
  ios_base::sync_with_stdio(0); cin.tie(0);

  cin>>n;
  for(i=1;i<=n;++i)
  {
    cin>>a[i];

    if(a[i]%n==0) return cout<<"1\n"<<i<<'\n',0;

    poz[a[i]%n]=i;

    if(poz[n-a[i]%n]) return cout<<"2\n"<<poz[n-a[i]%n]<<' '<<i<<'\n',0;

    sum[i]=sum[i-1]+a[i];

    if(poz[n-sum[i]%n])
    {
      for(j=1;j<=i;++j)
      if((sum[i]-sum[j-1])%n==0)
      {
        cout<<i-j+1<<'\n';
        for(int k=j;k<=i;++k) cout<<k<<" \n"[k==i];
        return 0;
      }
    }
  }

  cout<<"No idea\n";

 return 0;
}