/*************************************
*    author: marvinthang             *
*    created: 18.11.2024 12:07:03    *
*************************************/

#include <bits/stdc++.h>

using namespace std;

#define             fi  first
#define             se  second
#define           left  ___left___
#define          right  ___right___
#define   scan_op(...)  istream & operator >> (istream &in, __VA_ARGS__ &u)
#define  print_op(...)  ostream & operator << (ostream &out, const __VA_ARGS__ &u)
#define     file(name)  if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
#ifdef LOCAL
	#include "debug.h"
#else
	#define DB(...)
	#define db(...) ""
	#define debug(...)
#endif

namespace std {
template <class U, class V> scan_op(pair <U, V>) { return in >> u.first >> u.second; }
template <class T> scan_op(vector <T>) { for (size_t i = 0; i < u.size(); ++i) in >> u[i]; return in; }
template <class U, class V> print_op(pair <U, V>) { return out << '(' << u.first << ", " << u.second << ')'; }
template <size_t i, class T> ostream &print_tuple_utils(ostream &out, const T &tup) { if constexpr(i == tuple_size<T>::value) return out << ")"; else return print_tuple_utils<i + 1, T>(out << (i ? ", " : "(") << get<i>(tup), tup); }
template <class...U> print_op(tuple <U...>) { return print_tuple_utils<0, tuple <U...>>(out, u); }
template <class Con, class = decltype(begin(declval<Con>()))>typename enable_if <!is_same<Con, string>::value, ostream &>::type operator << (ostream &out, const Con &con) { out << '{'; for (__typeof(con.begin()) it = con.begin(); it != con.end(); ++it) out << (it == con.begin() ? "" : ", ") << *it; return out << '}'; }
template <class T> print_op(stack <T>) { vector <T> v; stack <T> st = u; while (!st.empty()) v.push_back(st.top()), st.pop(); reverse(v.begin(), v.end()); return out << v; }
template <class T> print_op(queue <T>) { queue <T> q = u; out << '{'; while (!q.empty()) { out << q.front(); q.pop(); if (!q.empty()) out << ", "; } out << '}'; return out; }
template <class T, class X, class Y> print_op(priority_queue <T, X, Y>) { priority_queue <T, X, Y> pq = u; out << '{'; while (!pq.empty()) { out << pq.top(); pq.pop(); if (!pq.empty()) out << ", "; } out << '}'; return out; }
template <class Fun> class y_combinator_result { Fun fun_; public: template <class T> explicit y_combinator_result(T &&fun): fun_(forward<T>(fun)) {} template <class...Args> decltype(auto)operator()(Args &&...args) { return fun_(ref(*this), forward<Args>(args)...); } };
template <class Fun> decltype(auto)y_combinator(Fun &&fun) { return y_combinator_result<decay_t<Fun>>(forward<Fun>(fun)); }
template <typename T, int D> struct Vec: public vector <Vec<T, D - 1>> { static_assert(D >= 1, "Vector dimension must be greater than zero!"); template <typename ...Args> Vec(int n = 0, Args ...args): vector <Vec<T, D - 1>>(n, Vec<T, D - 1>(args...)) {} };
template <typename T> struct Vec<T, 1>: public vector<T>{ Vec(int n = 0, const T &val = T()): vector<T>(n, val) {} };
#if __cplusplus < 202002L
	template <class T> int ssize(const T &a) { return a.size(); }
#endif
}

void process(void) {
	int n, m;
	cin >> n >> m;
	Vec<char, 2> a(n, m);
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			cin >> a[i][j];
		}
	}
	int k = n + m + 1 >> 1;
	Vec<char, 2> b(k, k, '#'), c(k, k, '#');
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			if ((i + j) & 1) {
				b[i + j >> 1][i - j + m >> 1] = a[i][j];
			} else {
				c[i + j >> 1][i - j + m >> 1] = a[i][j];
			}
		}
	}

	auto solve = [&](const Vec<char, 2>& b) {
		Vec<int, 4> f(k + 1, k + 1, k + 1, k + 1, -1);
		auto dp = y_combinator([&](auto dp, int x, int y, int u, int v) -> int {
			if (x >= u || y >= v) return 0;
			if (f[x][y][u][v] != -1) return f[x][y][u][v];
			int sz = (u - x) * (v - y);
			vector<int> value(sz + 1);
			for (int i = x; i < u; i++) {
				for (int j = y; j < v; j++) {
					if (b[i][j] == '#') continue;
					if (b[i][j] == 'B') {
						int a = dp(x, y, u, j);
						int b = dp(x, j + 1, u, v);
						if ((a ^ b) <= sz) value[a ^ b] = 1;
					} else if (b[i][j] == 'R') {
						int a = dp(x, y, i, v);
						int b = dp(i + 1, y, u, v);
						if ((a ^ b) <= sz) value[a ^ b] = 1;
					} else {
						int a = dp(x, y, i, j);
						int b = dp(x, j + 1, i, v);
						int c = dp(i + 1, y, u, j);
						int d = dp(i + 1, j + 1, u, v);
						if ((a ^ b ^ c ^ d) <= sz) value[a ^ b ^ c ^ d] = 1;
					}
				}
			}	
			int mex = 0;
			while (value[mex] > 0) ++mex;
			return f[x][y][u][v] = mex;
		});

		return dp(0, 0, k, k);
	};
	cout << ((solve(b) ^ solve(c)) ? "W" : "L");
	
}

int main(void) {
	ios_base::sync_with_stdio(false); cin.tie(nullptr);
	file("test");
	// int t; cin >> t; while (t--)
	process();
	return (0^0);
}