#include <stdio.h>
int main(void){
    long int a, m=100;
    do{
      scanf("%ld",&a);
    }while(a<101 || a>1000000000000000000);  
    long int i, r=1, count=0;
    while(r){
      m=m*1.01;
      count++;
      if(m>=a){
        r=0;  
      }
    }
    printf("%ld\n",count);
    return 0;
}