#include <stdio.h>

int main(void){
  long long int x;
  long long int money = 100;
  long long int year = 0;
  
  scanf("%lld",&x);
  
  while(money < x){
    money = money * 1.01;
    year++;
    //printf("%lld\n",money);
  }
  
  printf("%lld\n",year);
  
  return 0;
}