#include <stdio.h>

long long mi(long long x){
  return x += x/100;
}

int main()
{
  long long m=100,x;
  int count;

  scanf("%lld", &x);

  for(;;)
  {
    m = mi(m);
    count++;
    if(m >= x)
      break;
  }
  printf("%d",count);
}
