#include <stdio.h>

int main()
{

    long s;
    scanf("%ld", &s);

    long z = 100;

    int i;
    for (i = 1; z < s; i++)
    {
        z = z * 1.01;
        if(z>=s)
            break;
    }

        printf("%d",i);
    

    printf("\n");
}
