var f,g:text;
n,i,j,m,s:longint;
a:array[1..16,1..16]of integer;
begin
assign (f,'flip.in');reset (f);
assign (g,'flip.out');rewrite (g);
read (f,n,m);
for i:=1 to n do
for j:=1 to m do
                read (f,a[i,j]);
for i:=1 to n do
for j:=1 to m do
if a[i,j]>0 then s:=s+a[i,j];
write(g,s);
close (f);close (g);
end.