#include <stdio.h>

int main(void){
  
 unsigned long long x;
 scanf("%lld",&x);
 int s = 100;
 int count = 0;
  
  while(s < x){
    int temp = s;
    s = temp*1.01;
    count ++;
  }
  
  printf("%lld",count);
  
  return 0;
}
