var f,g:text;
    r,i,j,n:integer;
    a,min,s:longint;
    v:array[1..100] of boolean;
begin
s:=0;
assign(f,'cc.in');reset(f);readln(f,n);
for i:=1 to n do
v[i]:=true;
assign(g,'cc.out');rewrite(g);
for i:=1 to n do
begin
 min:=10001;
 for j:=1 to n do
  begin
  read(f,a);
  if (min>a) and (v[j]) then
  begin
  min:=a;
  r:=j;
  end;
  end;
 v[r]:=false;
 s:=s+min;
readln(f);
end;
write(g,s);
close(f);close(g);
end.