#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0;i<n;++i)

int main(){
    int n;
    cin>>n;
    vector<int>a(n);
    rep(i,n)cin>>a[i];
    int sum=0;
    vector<set<int>>v(32);
    auto add=[&](int x,int cnt){
        rep(j,32){
            if(x>>j&1){
                v[j].emplace(cnt);
            }
        }
        sum^=x;
    };
    auto erase=[&](int x,int cnt){
        rep(j,32){
            if(x>>j&1){
                v[j].erase(cnt);
            }
        }
        sum^=x;
    };
     auto next=[&](){
        assert(sum!=0);
        int x=31-__builtin_clz(sum);
        int idx=*v[x].begin();
        int cnt=a[idx]-(a[idx]^sum);
        erase(a[idx],idx);
        a[idx]-=cnt;
        add(a[idx],idx);
        cout<<idx+1<<" "<<cnt<<endl;
        int ret;
        cin>>ret;
        //cerr<<idx<<a[idx]<<sum<<endl;
        if(ret==-1)exit(0);
    };
    auto next2=[&](){
        assert(sum==0);
        int idx,k;
        cin>>idx>>k;
        idx--;
        erase(a[idx],idx);
        a[idx]-=k;
        add(a[idx],idx);
        int ret;
        cin>>ret;
        //cerr<<sum<<endl;
        if(ret==-1)exit(0);
    };

    rep(i,n)add(a[i],i);
    if(sum==0){
        cout<<0<<endl;
    }else{
        cout<<1<<endl;
        next();
    }
    while(1){
        next2();
        next();
    }
}