const n=4;
const m=2;
const x=2;
var a:array[1..n] of integer;
b:array[1..m,1..x] of integer;
i,j,d,f:integer;
begin
 d:=1;
 f:=1;
 
 for i:=1 to n do
 readln(a[i]);
 for i:=1 to n do
 begin
  if i mod 2=0 then
  begin
   b[1,d]:=a[i];
   d:=d+1;
  end;
 if i mod 2<>0 then
 begin
  b[2,f]:=a[i];
  f:=f+1;
 end;
end;
for i:=1 to m do
begin
 writeln;
 for j:=1 to x do
 write(b[i,j]);
end;
end.