#include <stdio.h>

int main(void){
    int money = 100;
    int year = 0;
    int target = 0;
    int i = 0;

    i = scanf("%d", &target);

    if(i == 0)
    {
        return 1;
    }

    while(money < target)
    {
        money = money + (money / 100);
        year++;
    }
    printf("%d", year);

    return 0;
}