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

int main(void){

    long int x, count, sum;
    count = 0;
    sum = 100;

    scanf("%ld",&x);

    while(1){
        sum += sum/100;
        count++;
        if(sum >= x){
            printf("%ld",count);
            break;
        }
    }

    return 0;
}