program hanibal;
var a,b,c,d,e,z:longint;
begin
d:=1000000000;
e:=0;
readln(a);
for z:=1 to a do
  begin
       readln(b,c);
       if (d>b) and (b>=0) then d:=b;
       if (e<c) then e:=c;
       writeln(d+e);
  end;
readln;
end.