#include<stdio.h>

int main(void){
    long long k_target;
    long long k = 100;
    long long year = 0;
    scanf("%lld", &k_target);
    while (k<k_target) {
        k = k *1.01;
        year++;
    }
    
    printf("%lld\n", year);
    return 0;
}
