program ural1048;
const
  maxn=1000000;
  inpath='';
  outpath='';
var
  a:array [0..maxn div 4] of integer;
  n:longint;
  i,j:longint;
  x,y:longint;
begin
  assign(input,inpath);
  reset(input);
  assign(output,outpath);
  rewrite(output);
  readln(n);
  for i:=1 to n mod 4 do
  begin
     read(x,y);
     a[0]:=a[0]*10+x+y;
  end;
  for i:=1 to n div 4 do
  begin
     for j:=1 to 4 do
     begin
        read(x,y);
        a[i]:=a[i]*10+x+y;
     end;
  end;
  for i:=n div 4 downto 1 do
  begin
     a[i-1]:=a[i-1]+a[i] div 10000;
     a[i]:=a[i] mod 10000;
  end;
  i:=0;
  while (a[i]=0) and (i<n div 4) do inc(i);
  write(a[i]);
  inc(i);
  for j:=i to n div 4 do
  begin
     if a[j]>=1000 then write(a[j])
    else if a[j]>=100 then write(0,a[j])
    else if a[j]>=10 then write('00',a[j])
    else write('000',a[j]);
  end;
  writeln;
  close(input);
  close(output);
end.