please int64 type or dword  ,using longint is wrong.
otherwise you will get a over data
this is a math method
you can prove it,or practise some examples and you will find
the orderliness
I like these problems ,if you have please send to me.
my e-mail : zhuyin_222@hotmail.com
//
program ex;
var   a,b:int64;
begin
    readln(a,b);
    if a<=b then writeln(2*(a-1))
    else writeln(2*b-1);
end.