read h w
read {a..d}
mapfile s
R=Q[--N]
W=Q[N++]
for(($W=a-++n,$W=b-1;N;)){
for((q=R,p=R;(p|q)>=0&&z[p*64+q]++<4;t=u<0|v?u*u<2:2,$W=p+n*t,$W=q+m*t,t=n,n=m,m=-t)){
t=1${s[p]:q:1} u=t-1${s[p+n]:q+m:1} v=t-1${s[p+n+n]:q+m+m:1}
}
}
NO
echo ${_[z[c*64+d-65]]-YES}