program madition;
var
  n,i,j,k,l:longint;
  a,b,c:string;
  f1,f2,f3:array[1..256]of longint;
  nn:longint;
  ss:set of char;
function ch(x:char):longint;
begin
  if x in ss then
    exit(ord(x)-ord('0'))
    else exit(ord(x)-ord('a')+10);
end;
procedure jia;
var
  i,j,q:longint;
begin
  q:=0;
  for i:=1 to k do
  begin
    f3[i]:=f1[i]+f2[i]+q;
    q:=f3[i] div n;
    f3[i]:=f3[i] mod n;
  end;
  if q<>0 then
  begin
    k:=k+1;
    f3[k]:=q;
  end;
end;
function bian(x:longint):char;
begin
  if x<10 then
    exit(chr(x+ord('0')))
    else exit(chr(x-10+ord('a')));
end;
begin
  assign(input,'madition.in');
  reset(input);
  assign(output,'madition.out');
  rewrite(output);
  readln(n);
  ss:=['0','1','2','3','4','5','6','7','8','9'];
  readln(a);
  readln(b);
  for i:=1 to length(a) do
    f1[length(a)-i+1]:=ch(a[i]);
  for i:=1 to length(b) do
    f2[length(b)-i+1]:=ch(b[i]);
  k:=length(a);
  l:=length(b);
  if k<l then k:=l;
  jia;
  for i:=1 to k do
    c[i]:=bian(f3[i]);
  for i:=k downto 1 do
    write(c[i]);
  writeln;
  close(input);
  close(output);
end.