#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#define ll long long
int main(void)
{
    ll i, x, st = 100;
    scanf("%lld", &x);
    i = 0;
    while (1)
    {
        if (st >= x)
            break;
        st = st * 1.01;
        i++;
    }
    printf("%lld\n", i);
    return 0;
}