#include<stdio.h>
int main()
{
    long long int k,i,c=0,m=100;
     
    scanf("%lld",&k);
    for ( i = 0;; i++)
    {
        m=m+((m*1)/100);
        c++;
        if(m>=k)
        {
            break;
        }
    }
    printf("%lld\n",c);
    
}