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

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, v = 0, p, x, s, M = 18;
    cin >> n;
    vector<int> a(n);
    vector<bitset<10000>> S(M);
    for(int i = 0; i < n; i++){
        cin >> a[i];
        v ^= a[i];
        for(int j = 0; j < M; j++){
            if(a[i] >> j & 1)S[j][i] = 1;
        }
    }
    auto update = [&](int p, int x){
        v ^= a[p];
        for(int j = 0; j < M; j++)S[j][p] = 0;
        a[p] -= x;
        v ^= a[p];
        for(int j = 0; j < M; j++){
            if(a[p] >> j & 1)S[j][p] = 1;
        }
    };
    auto my_turn = [&](){
        int p = S[__lg(v)]._Find_first();
        cout << p + 1 << " " << a[p] - (v ^ a[p]) << endl;
        update(p, a[p] - (v ^ a[p]));
    };
    if(v == 0){
        cout << 0 << endl;
        cin >> p >> x;
        update(--p, x);
    }else{
        cout << 1 << endl;
        my_turn();
        cin >> s;
        if(s == -1)return 0;
        cin >> p >> x;
        update(--p, x);
    }
    while(true){
        cin >> s;
        if(s == -1)return 0;
        my_turn();
        cin >> s;
        if(s == -1)return 0;
        cin >> p >> x;
        update(--p, x);
    }
}