#include #include #include using namespace atcoder; using mint = modint998244353; using namespace std; #define rep(i,n) for(int i=0;i<(n);i++) #define Inf 1000000001 int main(){ int _t; cin>>_t; rep(_,_t){ int h,w; cin>>h>>w; vector> ans(h,vector(w,0)); if(h==1||w==1){ int t = max(h,w); vector b; rep(i,t/3){ b.push_back(1); b.push_back(1); b.push_back(0); } if(t%3==1)b.insert(b.begin(),0); else if(t%3==2){ b.push_back(1); b.push_back(1); } rep(i,h){ rep(j,w){ ans[i][j] = b.back(); b.pop_back(); } } } else if(h==3&&w==3){ rep(i,h){ rep(j,w){ ans[i][j] = 2; } } ans[1][1] = 0; } else if(h*w==12 && min(h,w)==3){ rep(i,h){ rep(j,w){ if(i==0||j==0||i==h-1||j==w-1)ans[i][j] = 2; else ans[i][j] = 1; } } } else{ cout<<-1<