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


int main()
{
    long long int x,a,b;
    scanf("%ld",&x);
a = 100;
b = 0;
    while(1)
    {
        a = a*1.01;
        b++;
    if(a>=x)
        break;
    }
    printf("%ld",b);
    return 0;
}