program number(input,output);
 var
  i,j,k:longint;
  a:array [2..50000,1..10] of longint;
  b:array [1..21] of longint;
  n,m:longint;
  s:longint;
  ans:longint;
  min:longint;

procedure find(x,y,ans,f:longint);
 var
  i,j,k:longint;
  temp:longint;
begin
if (x=m) and (y=n) then begin
  ans:=ans+a[x,y];
   if (ans<min) then min:=ans;
end;


  for k:= 1 to 2 do
   begin
      if (x<=m) and (y<=n) then begin
     if k=2 then find(x+1,y,ans+a[x,y],1);
     if k=1 then find(x,y+1,ans+a[x,y],1);
   end;end;
     end;

begin
 s:=-1;
 assign(input,'number.in');
 assign(output,'number.out');
 reset(input);
 rewrite(output);
 readln(m,n);
  for i:=1 to m do
   for j:=1 to n do
    read(a[i,j]);
    ans:=a[1,1];
    min:=maxlongint;
   find(1,1,ans,1);
     if (ans>=0) then writeln(min)
      else writeln('-1');
   close(input);
   close(output);
 end.