#include<stdio.h>
#include<stdlib.h>
int main(){
  int unused __attribute__((unused));
  long long X,  y = 0, m = 100;
  unused = scanf("%lld", &X);

  while(m < X){
    m = m*1.01;
    y++;
  }
  printf("%lld", y);
  return 0;
}