program Tree;

{$APPTYPE CONSOLE}

var n,m,v:real;
f1,f2:text;
begin
assign(f1,'tree.dat');
reset(f1);
while not(eof(f1)) do
begin
readln(f1,n,m);
if n:=>2 then writeln(f2,'mismatch');
v:=(n+m)-1;
end;
close(f1);
assign(f2,'tree.sol');
rewrite(f2);
writeln(f2,v:6:2);
close(f2);
end.