#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define X first #define Y second #define pb push_back #define rep(X,Y) for (int (X) = 0;(X) < (int)(Y);++(X)) #define reps(X,S,Y) for (int (X) = (int)(S);(X) < (int)(Y);++(X)) #define rrep(X,Y) for (int (X) = (int)(Y)-1;(X) >=0;--(X)) #define rreps(X,S,Y) for (int (X) = (int)(Y)-1;(X) >= (int)(S);--(X)) #define repe(X,Y) for ((X) = 0;(X) < (Y);++(X)) #define peat(X,Y) for (;(X) < (Y);++(X)) #define all(X) (X).begin(),(X).end() #define rall(X) (X).rbegin(),(X).rend() #define eb emplace_back #define UNIQUE(X) (X).erase(unique(all(X)),(X).end()) #define Endl endl #define NL <<"\n" #define cauto const auto using namespace std; using ll=long long; using pii=pair; using pll=pair; template using vv=vector>; template inline bool MX(T &l,const T &r){return l inline bool MN(T &l,const T &r){return l>r?l=r,1:0;} //#undef NUIP #ifdef NUIP #include "benri.h" #else #define out(args...) #endif void ouT(ll x,int d=3){auto re=to_string(x);if((int)re.size()>d) re=x>0?"oo":"-oo";cout<vector table(int n, T v){ return vector(n, v);} template auto table(int n, Args... args){auto val = table(args...); return vector(n, move(val));} #endif template pair operator+(const pair &p,const pair &q){ return {p.X+q.X,p.Y+q.Y};} template pair& operator+=(pair &p,const pair &q){ p.X+=q.X; p.Y+=q.Y; return p;} template pair operator-(const pair &p,const pair &q){ return {p.X-q.X,p.Y-q.Y};} template pair& operator-=(pair &p,const pair &q){ p.X-=q.X; p.Y-=q.Y; return p;} template istream& operator>>(istream &is, pair &p){ is>>p.X>>p.Y; return is;} template T read(){ T re; cin>>re; return move(re);} template T read(const T &dec){ T re; cin>>re; return re-dec;} template vector readV(const int sz){ vector re(sz); for(auto &x:re) x=read(); return move(re);} template vector readV(const int sz, const T &dec){ vector re(sz); for(auto &x:re) x=read(dec); return move(re);} vv readG(const int &n,const int &m){ vv g(n); rep(_,m){ cauto a=read(1),b=read(1); g[a].pb(b); g[b].pb(a);} return move(g);} vv readG(const int &n){ return readG(n,n-1);} #define TT cauto TTT=read();rep(_,TTT) const ll MOD=1e9+7; //998244353; int main(){ ios_base::sync_with_stdio(false); cin.tie(0); cout< ps(m); for(auto &[a,b]:ps){ cauto n=read(); cauto vs=readV(n,1); for(cauto v:vs) a|=1ll< bss(50); cauto add= [&](ll a, ll b){ rep(d,50)if(a>>d&1 && bss[d].X) a^=bss[d].X, b^=bss[d].Y; out(a,b,1); if(!a){ if(b){ cout<<-1 NL; exit(0); } return false; } int i=0; while(~a>>i&1) ++i; rep(d,50)if(bss[d].X>>i&1) bss[d].X^=a, bss[d].Y^=b; bss[i]={a,b}; return true; }; for(cauto [a,b]:ps) add(a,b); rep(i,n) cout<