#include<stdio.h>
int main(void){
  int c = 0, y = 100, d = 0;
  long int X;
  scanf("%ld", &X);

  while(c == 0){
     y = y * 1.01;
     if(y >= X){
       c += 1;
       d += 1;
     }
     else d += 1;
  }

  printf("%d\n", d);


  return 0;
}