/* 165b.c */
#include <stdio.h>

int main(void){
    int x=0;
    int risi=0;
    int yokin=100;
    scanf("%d",&x);
    for(int i=0;i<yokin;i++){
        if(x<=yokin){
            printf("%d",i);
            return 0;
        }else{
            risi=yokin*1/100;
            yokin=yokin+risi;    
        }
        
    }
    printf("error");
}