#include <stdio.h>

int main() {
 long long int x;
  int yrs = 0;
  long long int y = 100;
  scanf("%lld", &x);
  while(y < x) {
  	yrs++;
    y = (long long int)(y*1.01);
  }
  printf("%d\n", yrs);
  return 0;
}