var i,A,B:integer;

ans:real;

f,g:text;

begin

assign(f,'input.txt');

assign(g,'output.txt');

reset(f);

rewrite(g);

readln(f,i);

read(f,A,B);

if (i=4) and (B=0)

then

begin

write(g,'Error');

close(g);

exit;

end;

if (i=5) and (B=0)

then

begin

write(g,'Error');

close(g);

exit;

end;

case (i) of

1:ans:=A+B;

2:ans:=A-B;

3:ans:=A*B;

4:ans:=A div B;

5:ans:=A mod B;

end;

write(g,ans);

close(f);

close(g);

end.