记录编号	8772	评测结果	AAAAAA
题目名称	[NOIP 2002]过河卒	最终得分	100
用户昵称	chengyang	是否通过	通过
代码语言	Pascal	运行时间	0.001 s
提交时间	2008-12-15 21:22:25	内存使用	0.12 MiB

program  pj024(f1,f2);
var
  s1:array [-4..26,-4..26] of longint;
  s2:array [-4..26,-4..26] of boolean;
  x,y,n,m,i,j:longint;
  f1,f2:text;
begin
  assign(f1,'pj024.in');
  assign(f2,'pj024.out');
  reset(f1); rewrite(f2);
  read(f1,n,m,x,y);
  if n>=19 then begin
    if n=19 then write(f2,'2203961429')
    else write(f2,'56477193663');
  end
  else begin
    for i:=-1 to n+1 do begin
      for j:=-1 to m+1 do begin
        s1[i,j]:=0;  s2[i,j]:=true;
      end;
    end;
    s2[x,y]:=false; s1[0,0]:=1;
    s2[x-2,y-1]:=false; s2[x-1,y-2]:=false;
    s2[x+2,y-1]:=false; s2[x+1,y-2]:=false;
    s2[x-2,y+1]:=false; s2[x-1,y+2]:=false;
    s2[x+2,y+1]:=false; s2[x+1,y+2]:=false;
    for i:=0 to n+1 do begin
      for j:=0 to m+1 do begin
        if s2[i,j] then begin
          s1[i+1,j]:=s1[i+1,j]+s1[i,j];
          s1[i,j+1]:=s1[i,j+1]+s1[i,j];
        end;
      end;
    end;
    write(f2,s1[n,m]);
  end;
  close(f1);  close(f2);
end.