#include<stdio.h>

int main(void){
    int k_target;
    int k = 100;
    int year=0;
    scanf("%d", &k_target);
    while (1) {
        k = k *1.01;
        year++;
        if(k>=k_target){
            break;
        }
    }
    
    printf("%d\n", year);
    return 0;
}
