get_string(String) :-
  current_input(Input),
  read_string(Input, ' \n', '', _, String).
 
get_number(Number) :-
  get_string(String),
  number_string(Number, String).
 
solve(Now,X,0) :- Now >= X, !.
solve(Now,X,Ans) :- N is Now * 101, Next is N//100, solve(Next,X,A), Ans is A + 1.

main :-
  get_number(X),
  solve(100,X,Ans),
  writeln(Ans).
  