#include <stdio.h>

int main(){
  unsigned long long int X;
  scanf("%lld",&X);
  unsigned long long int YOKIN=100;
  int year=0;
  while(1){
    year++;
    YOKIN = YOKIN*101/100;
    if(YOKIN >= X)break;
  }
  printf("%d",year);
  return 0;
}