from collections import deque

n, m = map(int, input().split())
sx, sy = 0, 0
gx, gy = n - 1, n - 1
INF = 10 ** 18

def bfs():
    d = [[-1] * n for i in range(n)]
    dx = [1, 0, -1, 0]
    dy = [0, 1, 0, -1]
 
    que = deque([])
    que.append((sy, sx))
    d[sy][sx] = 0
 
    while que:
        p = que.popleft()
        if p[0] == gy and p[1] == gx:
            exit(print("Yes"))
        for i in range(4):
            nx = p[0] + dx[i]
            ny = p[1] + dy[i]
            if nx == n - 1 and ny == n - 1: exit(print("Yes"))
            if 0 <= nx < n and 0 <= ny < n and d[nx][ny] == -1:
                print(nx + 1, ny + 1)
                res = input()
                if res == "Black":
                    que.append((nx, ny))
                    d[nx][ny] = 0
                    break
                else:
                    d[nx][ny] = 1
    return d[gy][gx]

print("Yes" if bfs() == 0 else "No")