#include <stdio.h>
int main() {
  int A,B,count;
  B = 100;
  count = 0;
  scanf("%d", &A);
  while (1)
  {
      count++;
      B = B*1.01;
      if(B >= A){
          printf("%d", count);
          break;
      } 

  }
  return 0;
}