#include <stdio.h>

int main(void)
{
        int x, i;
        double k;

        scanf("%d",&x);

        k=100;
        for(i=1;i>0;i++){
            k=k+k*0.01;
            if(k>x) break;
        }

        printf("%d\n",&i);
        return 0;
}
