#define _USE_MATH_DEFINES
#include  <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <string>
#include<math.h>
#include<iomanip>
#include<stdio.h>
#include <stdlib.h>
#include<stdio.h>
#include <queue>
#include<map>
#include <fstream>
#include <sstream>
#include<set>
#include<stack>
#include<time.h>
#include <sys/types.h>
#include <tuple>
#include <numeric>
#include <iterator>

typedef long long int ll;
//#include<bits/stdc++.h>


using namespace std;





int main()
{

    int Q;
    Q = 1;
    //cin >> Q;


    while (Q--) {
        int w, h;
        char c;
        cin >> w >> h >> c;
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                cout << c;
                if (w % 2==0 && j == w - 1)break;
                if (c == 'B')c = 'W';
                else c = 'B';
            }
            cout << endl;
        }
    }
    return 0;
}