def question(a,b):
    print(a,b,flush=True)
    ans=input()

    if ans[0]=="B":
        return 1
    elif ans[0]=="W":
        return 0
    else:
        exit()

def answer(ans):
    exit(print(ans,flush=True))
#=================================================
from collections import deque
N,M=map(int,input().split())

# 自明な否定
if 2*N-1>M:
    answer("No")

X=[[-1]*(N+1) for _ in range(N+1)]
X[1][1]=X[N][N]=1
Remain=M-2

Q=deque([(1,1)])
T=[(1,0),(-1,0),(0,1),(0,-1)]

while Q:
    x,y=Q.popleft()

    if Remain==0:
        break

    if X[N][N]!=-1:
        break

    for a,b in T:
        p=x+a; q=y+b
        if 1<=p<=N and 1<=q<=N and X[p][q]==-1 and (N-p)+(N-q)<=Remain:
                X[p][q]=quest=question(p,q)

                if quest:
                    Q.append((p,q))
                    Remain-=1

answer("Yes" if X[N][N]==1 else "No")