#include<iostream> #include<sstream> #include<fstream> #include<string> #include<vector> #include<deque> #include<queue> #include<stack> #include<set> #include<map> #include<algorithm> #include<functional> #include<utility> #include<bitset> #include<cmath> #include<cstdlib> #include<ctime> #include<cstdio> using namespace std; #define REP(i,n) for(int i=0;i<int(n);i++) #define foreach(c,itr) for(__typeof((c).begin()) itr=(c).begin();itr!=(c).end();itr++) typedef long long ll; typedef pair<int,int> P; int a[80000]; int main(void){ int i,j; cin.tie(0); ios_base::sync_with_stdio(false); int n,x=0; cin >> n; for (i=1;i<=n;i++){ cin >>a[i]; x^=a[i]; } int t; if(x!=0) t=1; else t=0; cout << t << endl; cout.flush(); if(t==1){ while(1){ int p; for(j=14;j>=0;j--){ if(x & (1<<j)){ p=j; break; } } int q; for(i=1;i<=n;i++){ if(a[i] & (1<<p)){ q=i; break; } } int s=x; x=x^a[q]; int k=a[q]-(a[q]^s); a[q]=s^a[q]; x=x^a[q]; cout << q << ' ' << k << endl; cout.flush(); int r; cin >> r; if(r==-1) return 0; int c,d; cin >> c >> d; x=x^a[c]; a[c]=a[c]-d; x=x^a[c]; cin >> r; if(r==-1) return 0; } }else{ while(1){ int c,d; cin >> c >> d; x=x^a[c]; a[c]=a[c]-d; x=x^a[c]; int r; cin >> r; if(r==-1) return 0; int p; for(j=14;j>=0;j--){ if(x & (1<<j)){ p=j; break; } } int q; for(i=1;i<=n;i++){ if(a[i] & (1<<p)){ q=i; break; } } int s=x; x=x^a[q]; int k=a[q]-(a[q]^s); a[q]=s^a[q]; x=x^a[q]; cout << q << ' ' << k << endl; cout.flush(); cin >> r; if(r==-1) return 0; } } return 0; }