#include <stdio.h>
#include <stdlib.h>

int main(void){
    long long int X;

    scanf("%lld",&X);


    long long int money=100;
    int absmoney=100;
    int year;


 
    year=0;
    while(money<X){
        money+=money/100;
        year++;
        //absmoney=abs(money);
    }

    printf("%d",year);
    return 0;


}