#include <math.h>
#include <stdio.h>
#include <string.h>
long long a;
double n = 100;
int count = 0;
int main(void) {
    scanf("%lld", &a);
    while (1) {
        n = n * 1.01;
        floor(n);
        count++;
        if (n >= a) {
            printf("%d\n", count);
            break;
        }
    }
}