#include<stdio.h>
int main()
{
    unsigned long long int x,y=0,i=100;
    scanf("%ull",&x);
    while(1){
    i=i+(i*0.01);
    y++;
       
        
     }
    if(i>=x){
        printf("%ull",y);
    }
    
    
    
    return 0;
}