const modp=998244353;
var t,l,n,i,j:longint;
    ans:int64;
    up,down,max,min:array[0..100000] of longint;
    flag:array[1..100000] of boolean;
procedure tryit;
var i:longint;
begin
  fillchar(flag,sizeof(flag),true);
  ans:=1;
  if (up[1]<>down[1]) then
  begin
    writeln('0');
    exit;
  end;
  max[1]:=up[1];
  min[1]:=up[1];
  for i:=2 to n do
  begin
    if ((up[i]<>up[i-1]) and (down[i]<>down[i-1]) and (up[i]<>down[i])) or (down[i]>down[i-1]) or (up[i]<up[i-1]) then
    begin
      writeln('0');
      exit;
    end;
    if (up[i]<>up[i-1]) then
    begin
      max[i]:=up[i];
      min[i]:=up[i];
    end
    else if (down[i]<>down[i-1]) then
    begin
      max[i]:=down[i];
      min[i]:=down[i];
    end
    else
    begin
      max[i]:=up[i];
      min[i]:=down[i];
      flag[i]:=false;
    end;
    if not(flag[i]) then ans:=int64(ans*(max[i]-min[i]+2-i));
if (max[i]-min[i]+2-i<0) and not(flag[i]) then
begin
  writeln('0');
  exit;
end
else ans:=ans mod modp;
  end;
  writeln(ans);
end;
begin
  readln(t);
  for l:=1 to t do
  begin
    fillchar(up,sizeof(up),0);
    fillchar(down,sizeof(down),0);
    fillchar(max,sizeof(max),0);
    fillchar(min,sizeof(min),0);
    readln(n);
    for i:=1 to n do
        read(down[i]);
    readln;
    for i:=1 to n do
        read(up[i]);
    readln;
    tryit;
  end;
end.