var a,b,c,d:longint;
begin
read(a);
b:=a mod 10;
c:=a div 10 mod 10;
d:=a div 100;
if (b>c)and(b>d)and(c<b)and(c<d) then write(b-c);
if (b>c)and(b>d)and(d<b)and(d<c) then write(b-d);
if (d>c)and(d>b)and(c<b)and(c<d) then write(d-c);
if (d>c)and(d>b)and(b<c)and(b<d) then write(d-b);
if (c>b)and(c>d)and(b<c)and(b<d) then write(c-b);
if (c>b)and(c>d)and(d<b)and(d<c) then write(b-c);
end.
/**************************************************************
	Problem: 1667
	User: admin
	Language: Pascal
	Result: Wrong Answer
****************************************************************/