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

int main(void){
    long     x;
    long     money = 100;
    int     cnt=0;

    scanf("%ld",&x);
    while (money <= x)
    {
        money += money / 100;
        cnt++;
    }
    printf("%ld\n",cnt);
    return(0);
}