program fibonachi;

{$APPTYPE CONSOLE}
uses
  SysUtils;

var s,a1,a2,a3:int64;
f1,f2,f3:string;
max,j,n,m,i:integer;
function s3(s1,s2:string):string;
var t,s4:string;
ost,a,i:integer;
begin
while length(s1)<>length(s2) do
if   length(s1)<length(s2)  then s1:='0'+s1 else s2:='0'+s2;
s4:='';
ost:=0;
for i:=length(s1) downto 1 do  begin
a:=(ord(s1[i])-ord('0')+ord(s2[i])-ord('0')+ost)mod 10;
ost:=(ord(s1[i])-ord('0')+ord(s2[i])-ord('0')+ost)div 10;
s4:=inttostr(a)+s4 ;
end;
if ost >0 then s4:=inttostr(ost)+s4 ;
s3:=s4;
end;

begin
//assign(input,'TABLE.dat');
//reset(input);
//assign(output,'TABLE.sol');
//rewrite(output);

readln(n);

f[1,1]:='1';
f[1,2]:='1';
for i:=3 to m do
f[1,i]:=s3(f[1,i-1],f[1,i-2]);

f[2,1]:='1';
for i:=3 to n do
f[i,1]:=s3(f[i-1,1],f[i-2,1]);




for i:=2 to n do
 for j:=2 to m do
f[i,j]:=s3(s3(f[i-1,j],f[i-2,j]),s3(f[i,j-1],f[i,j-2]));



writeln(f[n,m]);
close(input);
close(output);

end.