#include <stdio.h>
int main() {
  long long int criteria;
  scanf("%lld", &criteria);
  long long int cmoney=100;
  long long int n=0;
  for (;cmoney < criteria;n++,cmoney *= 1.01){}
  //printf("%lld\n", a);
  printf("%lld", n);
  return 0;
}