#include <stdio.h>

int main(){
  long long x,a[5000];
  scanf("%d",&x);
  a[0]=100;
  for(int i=1;i>0;i++){
    a[i]=a[i-1]+(a[i-1]-(a[i-1]%100))/100;
    if(a[i]>=x){printf("%d",i);return 0;}
  }
}
