program kupa;
var
tb1:array [1..1000000] of byte;
tb2:array [1..1000000] of byte;
wyn:array [1..1000001] of byte;
x,y,n,z:longint;
p:byte;
begin
readln(n);
for x:=1 to n do
 readln(tb1[x],tb2[x]);
for x:=n downto 1 do
 begin
 if tb1[x]+tb2[x]+p>9 then
  begin
  wyn[x+1]:=tb1[x]+tb2[x]-10+p;
  p:=1;
  end
  else
  begin
  wyn[x+1]:=tb1[x]+tb2[x]+p;
  p:=0;
  end;
 end;
 if p=1 then wyn[1]:=1;
 z:=1;
 while (wyn[z]=0)and(z<n+1)do
 begin
 z:=z+1;
 end;
 begin
 for y:=z to n+1 do
 write(wyn[y]);writeln;
 end;
end.