var a,b,c,d,e,f:integer;
begin
 readln(a,b,c,d,e,f);
if ((a+b+c)-(d+e+f))=1  then writeln ('Yes') else
if ((d+e+f)-(a+b+c))=1 then
writeln ('Yes') else writeln ('No');
end.

That's a wrong program. |(a+b+c)-(d+e+f)| always is 1, so your program should always print '1'.