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

  while(c == 0){
     y = y * 101 / 100;
     if(y >= X){
       c += 1;
       d+= 1;
     }
     else d += 1;
  }

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


  return 0;
}