#include <stdio.h>

int main(void){
    long long int x;
    int i = 0;
    long long int money = 100;
    scanf("%lld",&x);
    while(1){
        i++;
        money = money*1.01;
        if(x <= money){
            printf("%d",i);
            break;
        }
    }
    return 0;
}