#include <stdio.h>

int main(void)
{
  int x;
  int money = 100;
  scanf("%d", &x);
  for(int i=1;i<=10000000000000;i++){
    money = money * 1.01;
    if(money >= x){
      printf("%d\n", i);
      break;
    }
  }
  return 0;
}