program one;
var a,b:integer;
begin
read(a);
if a div 10 >a mod 10 then
b:=a div 10-a mod 10
else if a div 10< a mod 10 then
b:=a mod 10-a div 10;
writeln('b = ',b);
end.
program one;
var a,b:integer;
begin
read(a);
if a div 10 >a mod 10 then
b:=a div 10-a mod 10
else if a div 10< a mod 10 then
b:=a mod 10-a div 10;
writeln('b = ',b);
end.