#include using namespace std; using ll = long long; using ld = long double; using ull = unsigned long long; #define rep(i,n) for(ll i=0;i T div_floor(T a, T b) { return a / b - ((a ^ b) < 0 && a % b); } template T div_ceil(T a, T b) { return a / b + ((a ^ b) > 0 && a % b); } template inline bool chmin(T &x, U y) { return (y < x) ? (x = y, true) : false; } template inline bool chmax(T &x, U y) { return (x < y) ? (x = y, true) : false; } void solve() { ll H,W; cin>>H>>W; vector S(H,string(W,'O')); rep(i,H){ rep(j,W){ if ((i+j/2)%2==0){ S[i][j]=='O'; } else{ S[i][j]='X'; } } } rep(i,H){ cout<