#include <stdio.h>

int main(void)
{
  int Ganpon = 100;
  int Target;
  int i = 0;
  scanf("%d",&Target);

  if(101 <= Target && Target <= 1000000000000000000)
  {
    while(Target > Ganpon)
    {
      Ganpon = Ganpon * 1.01;
      i++;
    }
    printf("%d",i);
  }

  return 0;
}