#include <stdio.h>
int main(){
  int a;
  scanf("%d", &a);

  int bank = 100;
  int year = 0;
  int rishi = (int)bank/100;
  while(1){
      year++;
    if((int)year/100>rishi)
      rishi++;
    bank+=rishi;
    if(bank==a)
      break;
  }
  printf("%d", year);
}