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

int main(){

    double x;
    scanf("%lf",&x);
    double n;
    int s;

    n = (log10(x) - 2)/(log10(101) -2);
    s = (int)n;

    if( s-n == 0){
        printf("%d",s);
    } else {
        int l = s + 1;
        printf("%d",l);
    }
    return 0;

}