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#include <bits/stdc++.h>
#define f first
#define s second
#define LL long long
#define ALL(V) V.begin(),V.end()
#define boost ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define endl "\n"
#define de(x) cout<<#x<<": "<<x<<endl
using namespace std;
const LL N=1e6+69, base=1024*1024,mod=1e9+7;
int t[N];
int main(void) {
    boost;
    int n;
    cin>>n;
    for(int i = 0;i < n;i++) {
        int a;
        cin>>a;
        t[a]++;
    }
    cout<<2-min(t[1],2)<<endl;
    cout<<2<<endl;
    cout<<1<<" "<<2<<endl;
}