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

int main(void){
    int X;

    scanf("%d",&X);


    int money=100;
    int absmoney=100;
    int year=0;

    for(;;){
        year++;
        money=money+abs(money*0.01);
        if(money>=X){
            break;
        }
        //absmoney=abs(money);

    }

 

    // while(money<X){
    //     money=absmoney*1.01;
    //     year++;
    //     absmoney=abs(money);
    // }

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


}