const maxn=50;
type hl=array[1..maxn] of 0..1;
var data:array[1..maxn,1..maxn] of longint;
    f:array[1..maxn,1..maxn] of 0..1;
    h,l:hl;
    i,j,k,n,m:longint;
    color:array[1..maxn,1..maxn] of char;

function min(r,t:longint):longint;
  begin
    if r<t then min:=r else min:=t
  end;

procedure make(x,y:longint);
  begin
    for k:=min((m-i) div x,(n-j) div y) downto 1 do

      f[i+k*x,j+k*y]:=1-f[i+k*x,j+k*y];

    for k:=min((m-i) div x,(j-1) div y) downto 1 do

      f[i+k*x,j-k*y]:=1-f[i+k*x,j-k*y];

    for k:=min((i-1) div x,(j-1) div y) downto 1 do

      f[i-k*x,j-k*y]:=1-f[i-k*x,j-k*y];

    for k:=min((i-1) div x,(n-j) div y) downto 1 do

      f[i-k*x,j+k*y]:=1-f[i-k*x,j+k*y]

  end;

begin
  assign(input,'input.in'); reset(input);
  readln(m,n);
  for i:=1 to m do
    begin
      for j:=1 to n do read(color[i,j]);
      readln
    end;
  for i:=1 to m do for j:=1 to n do read(data[i,j]);
  close(input);

  fillchar(h,sizeof(h),0); l:=h;
  fillchar(f,sizeof(f),0);

  for i:=1 to m do
    for j:=1 to n do
        if odd(data[i,j]) then begin
          h[i]:=1-h[i];
          l[j]:=1-l[j];
          make(3,4); make(4,3); make(5,12); make(12,5)
        end;
  for i:=1 to m do
    begin
      for j:=1 to n do
        if color[i,j]='W' then if odd(h[i]+l[j]+f[i,j]+data[i,j])
then write('B') else write('W')
          else if odd(h[i]+l[j]+f[i,j]+data[i,j]) then write('W')
else write('B');
      writeln
    end
end.

very obvious mistake,there are other numbers fit x*x+y*y=z*z
for example 7*7+24*24=25*25
8*8+15*15=17*17