###
function f(a,b:int):int:=
if a>b then 0
else
  if a=b then 1 
else
  f(a+1,b)+if a mod 100 div 10 < a mod 10 then f((a mod 10 *10)+ (a mod 100 div 10)+(a div 100 * 100),b) else 0;
print(f(101,154))