include<bits/stdc++.h>

using namespace std; long long a[100000001],n,i,j=2,d; int c=1e2; int main () { cin>>n; for (i=0; i<n; i++) cin>>a[i]; for (i=0; i<n; i++){ c=a[i]%j; d=a[i+1]%j; if (c==d) cout<<j<<" "; j+=2;} return 0; }