#pragma GCC target("avx2") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") #include #include using namespace std; using namespace atcoder; typedef long long ll; #define rep(i, n) for (int i = 0; i < (int)(n); i++) #define repr(i, n) for (int i = (int)(n) - 1; i >= 0; i--) #define repk(i, k, n) for (int i = k; i < (int)(n); i++) #define all(v) v.begin(), v.end() #define mod1 1000000007 #define mod2 998244353 #define mod3 100000007 #define vi vector #define vs vector #define vc vector #define vl vector #define vb vector #define vvi vector> #define vvc vector> #define vvl vector> #define vvb vector> #define vvvi vector>> #define vvvl vector>> #define pii pair #define pil pair #define pli pair #define pll pair #define vpii vector> #define vpll vector> #define vvpii vector>> #define vvpll vector>> template void debug(T e){ cerr << e << endl; } template void debug(vector &v){ rep(i, v.size()){ cerr << v[i] << " "; } cerr << endl; } template void debug(vector> &v){ rep(i, v.size()){ rep(j, v[i].size()){ cerr << v[i][j] << " "; } cerr << endl; } } template void debug(vector> &v){ rep(i,v.size()){ cerr << v[i].first << " " << v[i].second << endl; } } template void debug(set &st){ for (auto itr = st.begin(); itr != st.end(); itr++){ cerr << *itr << " "; } cerr << endl; } template void debug(multiset &ms){ for (auto itr = ms.begin(); itr != ms.end(); itr++){ cerr << *itr << " "; } cerr << endl; } template void debug(map &mp){ for (auto itr = mp.begin(); itr != mp.end(); itr++){ cerr << itr->first << " " << itr->second << endl; } } void debug_out(){ cerr << endl; } template void debug_out(Head H, Tail... T){ cerr << H << " "; debug_out(T...); } int main(){ int n; cin >> n; vi a(n); rep(i,n) cin >> a[i]; int grundy = 0; rep(i,n) grundy ^= a[i]; int flag = 0; if (grundy == 0){ cout << 0 << endl; flag = 0; } else{ cout << 1 << endl; flag = 1; } while(true){ if (flag == 1){ int idx = 0, k = 0; for (int i = 0; i < n; i++){ for (int j = 0; j <= a[i]; j++){ if (((grundy ^ a[i]) ^ (a[i] - j)) == 0){ //debug_out(grundy, a[i], a[i] - j); idx = i; k = j; } } } cout << idx + 1 << " " << k << endl; grundy ^= a[idx]; a[idx] -= k; grundy ^= a[idx]; int ret; cin >> ret; if (ret == -1){ return 0; } flag ^= 1; } else{ int i, k; cin >> i >> k; grundy ^= a[i - 1]; a[i - 1] -= k; grundy ^= a[i - 1]; int ret; cin >> ret; if (ret == -1){ return 0; } flag ^= 1; } debug(grundy); debug(a); } }