#include <stdio.h>
#include <math.h>

int main(int argc, char const *argv[])
{
    long double x;
    unsigned long long yokin = 100;
    unsigned long c = 0;
    scanf("%Lf", &x);

    while (yokin < x)
    {
        yokin *= 1.01;
        c++;
    }
    printf("%lu\n", c);
    return 0;
}
