#define MD 998244353
ll@H,@W,B[3]{},Q[]{},k;string@S[H];rep[S,i](s,H)rep[s,j](c,W)B[k=(i+j)%3]^=c==66,Q[k]+=c<66;Mint t=2;wt(mul[i,0,3](Q[i]?t**(Q[i]-1):B[i]*t/2));