function Main(input) {
    var inputArr = input.split('\n')[0].split(' ');
    var w = +inputArr[0];
    var h = +inputArr[1];
    var i = (inputArr[2] === 'W') ? 1 : 0;

    var tmp = '';
    var x;
    var y;
    for(y = 0; y < h; y++) {
        for(x = 0; x < w; x++) {
            tmp += (((x+y)%2)^i) ? 'W' : 'B' ;
        }
        tmp += '\n'
    }

    ans = tmp;

    console.log(ans);
}

// Don't edit this line!
Main(require("fs").readFileSync("/dev/stdin", "utf8"));