#include <stdio.h>
#include <math.h>

int main(void){

  long x;
  scanf("%ld", &x);
  long takahashi = 100;
  for (long i = 1; ; i++) {
    takahashi *= 101;
    takahashi /= 100;
    if (takahashi >= pow(10,15)) {
      takahashi /= pow(10,8);
      x /= pow(10,8);
    }
    if (takahashi >= x) {
      printf("%ld\n", i);
      break;
    }
  }

  return 0;
}