#include <bits/stdc++.h> using namespace std; using ll = long long; using ld = long double; using pcc = pair<char,char>; using pii = pair<int,int>; using pll = pair<ll,ll>; using pdd = pair<ld,ld>; using tuplis = array<ll,3>; template<class T> using prique = priority_queue<T,vector<T>,greater<T>>; #define rep(i,n) for(ll i = 0; i < n; i++) #define rrep(i,n) for(ll i = n-1; i >= 0; i--) #define all(a) a.begin(),a.end() #define rall(a) a.rbegin(),a.rend() #define Sort(a) sort(all(a)) #define Rev(a) reverse(all(a)) #define Uniq(a) sort(all(a));a.erase(unique(all(a)),a.end()) const ll LINF = 1001001001001001001; const int INF = 1001001001; const int MOD = 1000000007; const int MODD = 998244353; const ld PI = 3.1415926535897932; const ll dx[] = {0, 1, 0, -1, 1, -1, 1, -1}; const ll dy[] = {1, 0, -1, 0, 1, 1, -1, -1}; inline ll popcnt(ll a){ return __builtin_popcountll(a); } inline ll intpow(ll a, ll b){ ll ans = 1; while(b){ if(b & 1) ans *= a; a *= a; b /= 2; } return ans; } inline ll modpow(ll a, ll b, ll p){ ll ans = 1; while(b){ if(b & 1) (ans *= a) %= p; (a *= a) %= p; b /= 2; } return ans; } ll gcd(ll a,ll b){ if(a%b == 0){return b; } else{ return gcd(b,a%b); } } ll lcm(ll a,ll b){ return a/gcd(a,b)*b; } template<class T> bool chmin(T& a, const T& b){ if(a > b){ a = b; return 1; } return 0; } template<class T> bool chmax(T& a, const T& b){ if(a < b){ a = b; return 1; } return 0; } template<class T, class U> bool chmin(T& a, const U& b){ if(a > T(b)){ a = b; return 1; } return 0; } template<class T, class U> bool chmax(T& a, const U& b){ if(a < T(b)){ a = b; return 1; } return 0; } int main() { int W,H; char C; cin >> W >> H >> C; rep(i,H) { rep(j,W) { if((i+j)%2 == 0) { cout << C; } else { cout << ((C == 'B')?'W':'B'); } } cout << endl; } }