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

int main(void){
    int X;

    scanf("%d",&X);


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

 

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

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


}








