#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define vvi vector<vector<int>>
#define vec vector
#define pq priority_queue
#define all(v) (v).begin(), (v).end()
#define uniqueV(x) sort(x.begin(), x.end()); x.erase(unique(x.begin(), x.end()), x.end());
#define rep(i, n) for (int (i) = (0); (i) < (n); ++(i))
#define repp(i, m, n) for (int (i) = (m); (i) < (n); ++(i))
#define debug(x) cerr << #x << ": " << x << endl;
#define debug2(x, y) cerr<<"("<<#x<<", "<<#y<<") = "<<"("<<x<<", "<<y<<")"<<endl;
#define debug3(x, y, z) cerr<<"("<<#x<<", "<<#y<<", "<<#z<<") = "<<"("<<x<<", "<<y<<", "<<z<<")"<<endl;
#define debugB(value, size) cerr<<#value<<": "<<bitset<size>(value) << endl;
#define line() cerr << "---------------" << endl;

const int dx[] = {1, -1, 0, 0};
const int dy[] = {0, 0, -1, 1};
const double PI = 3.14159265358979323846;

template<typename T>
void printA(vector<T> &printArray, char between = ' ') {
   int paSize = printArray.size();
   for (int i = 0; i < paSize; i++) { cerr << printArray[i] << between;}
   if (between != '\n') {cerr << endl;}
}

// ------------------------------------------------------------------------------------------

int W, H;
char C;
char B[55][55];

int main() {
   cin >> W >> H >> C;

   string a, b;
   rep (i, W) {
      if (i&1) {
         a += 'B';
      } else {
         a += 'W';
      }
   }
   rep (i, W) {
      if (i&1) {
         b += 'W';
      } else {
         b += 'B';
      }
   }

   if (C == 'W') {
      rep (i, H) {
         if (i % 2 == 0) {
            cout << a << endl;
         } else {
            cout << b << endl;
         }
      }
   } else {
      rep (i, H) {
         if (i % 2 == 0) {
            cout << b << endl;
         } else {
            cout << a << endl;
         }
      }
   }

   return 0;
}