#include <stdio.h>

int main(int argc, char const *argv[])
{
  unsigned long long X;
  scanf("%llu", &X);

  unsigned long long money = 100;
  unsigned int count = 0;
  while (money < X)
  {
    money += money / 100;
    count++;
  }
  printf("%d", count);

  return 0;
}