#include<stdio.h>

int main(void){
    int  c;
    unsigned long int x, sum;
    sum = 100;
    scanf("%lu", &x);
    c = 0;
    while (sum < x)
    {
        sum = sum * 1.01;
        c++;
    }
    printf ("%d\n", c);
    
    return 0;
}