program ministry;
const
 maxn=500;
 max=1000000000;
var
 map:array[1..5,1..5]of longint;
 back:array[1..5,1..5]of integer;
 p:array[1..5,1..5]of longint;
 t:array[1..5]of longint;
 m,n:integer;
procedure init;
var
 i,j:integer;
begin
 readln(m,n);
 for i:=1 to m do
  begin
   for j:=1 to n do
    read(map[j,i]);
   readln;
  end;
end;
procedure solve;
var
 i,j,k:integer;
 min:longint;
begin
 for i:=2 to m do
  for j:=0 to n+1 do
   p[j,i]:=Max;
 for i:=1 to n do
  p[i,1]:=map[i,1];
 for i:=2 to m do
  for j:=1 to n do
   begin
    p[j,i]:=p[j,i-1]+map[j,i];
    back[j,i]:=j;
    if j>1 then
     begin
      t[j-1]:=map[j-1,i]+map[j,i];
      if t[j-1]+p[j-1,i-1]<p[j,i] then
       begin
        p[j,i]:=t[j-1]+p[j-1,i-1];
        back[j,i]:=j-1;
       end;
     end;
    if j>2 then
     for k:=j-2 to 1 do
      begin
       t[k]:=t[k+1]+map[k,i];
       if t[k]+p[k,i-1]<p[j,i] then
        begin
         p[j,i]:=t[k]+p[k,i-1];
         back[j,i]:=k;
        end;
      end;
    if j<n then
     begin
      t[j+1]:=map[j,i]+map[j+1,i];
      if t[j+1]+p[j+1,i-1]<p[j,i] then
       p[j,i]:=t[j+1]+p[j+1,i-1];
     end;
    for k:=j+2 to n do
     begin
      t[k]:=t[k-1]+map[k,i];
      if t[k]+p[k,i-1]<p[j,i] then
       p[j,i]:=t[k]+p[k,i-1];
     end;
  end;

end;
begin
 init;
 solve;
end.