var a,b:string;
    x,y,z:array [1..1001] of integer;
    i,f,nx,ny,nz:longint;

begin
    readln(a);
    readln(b);
    nx:=length(a);
    ny:=length(b);
    for i:=1 to nx do
          val(a[i],x[nx-i+1],f);

    for i:=1 to ny do
          val(b[i],y[ny-i+1],f);
    if nx>ny then nz:=nx
                         else nz:=ny;
    for i:=1 to nz do
         begin
          z[i]:=z[i]+y[i]+x[i];
          if z[i]>9 then begin z[i]:=z[i] mod 10;z[i+1]:=1;end;
         end;
    if z[nz+1]<>0 then nz:=nz+1;
    for i:=nz downto 1 do
         write(z[i]);
end.

var f:array[0..1000]of int64;
n,i:longint;
begin
readln(n);
f[1]:=1;
f[2]:=3;
f[3]:=5;
for i:=4 to n do
f[i]:=f[i-1]+f[i-2];
writeln(f[n]);
end.