#include <stdio.h>

int main(void) {
  int ans;
  ans=0;
  long long int x,yokin;
  yokin=100;
  scanf("%lld",&x);
  while(yokin<x)
    {
      ans++;
      yokin*=101;
      yokin/=100;
    }
    printf("%d\n",ans);
  return 0;
}