记录编号	8419	评测结果	WWAWWWWWWW
题目名称	[BYVoid S3] 艾萨拉的激流	最终得分	10
用户昵称	0彼岸0	是否通过	未通过
代码语言	Pascal	运行时间	6.200 s
提交时间	2008-11-14 08:09:24	内存使用	76.49 MiB

const
  maxw=1000;
  maxl=10000;
var
  map:array[0..maxl+1,0..maxw+1] of longint;
  dp:array[1..maxl,1..maxw] of longint;
  w,l,i,j,k,t,n,ans:longint;
function max(a,b,c:longint):longint;
  begin
    if (a>=b)and(a>=c) then exit(a)
      else
        if (b>=a)and(b>=c) then exit(b)
          else exit(c);
  end;
begin
  assign(input,'azshara.in'); assign(output,'azshara.out');
  reset(input); rewrite(output);
  fillchar(map,sizeof(map),255);
  fillchar(dp,sizeof(dp),255);
  readln(w,l);
  for i:=1 to l do
    begin
      for j:=1 to w do read(map[i,j]);
      readln;
    end;
  for i:=1 to w do dp[l,i]:=map[l,i];
  for i:=l-1 downto 1 do
    for j:=1 to w do
        if map[i,j]<>-1 then
          dp[i,j]:=max(dp[i+1,j],dp[i+1,j+1],dp[i+1,j-1])+map[i,j]
            else dp[i,j]:=map[i,j];
  ans:=0;
  for i:=1 to w do if dp[1,w]>ans then ans:=dp[1,w];
  write(ans);
  close(input); close(output);
end.