#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>
#include <limits.h>

#define max  1000

//qsort(str, n, sizeof(int), up_comp);
int up_comp(const void *a, const void *b){return *(int*)a - *(int*)b;}
int down_comp(const void *a, const void *b){return *(int*)b - *(int*)a;}
int count_digit(int a){int i=0;while(a!=0){a=a/10;i++;}return i;}
int euclid( int a, int b ){int temp;if(a<b){temp=a;a=b;b=temp;}if(b<1)return -1;if(a%b==0) return b;return euclid(b,a%b);}
int int_sort( const void * a , const void * b ) {
  return strcmp(( char * )a , ( char * )b );
}

int main()
{
    long long int x, ctmp=100, y=0;
    
    scanf("%lld", &x);
    
    while (ctmp<x) {
        ctmp+=ctmp*0.01;
        y++;
    }
    
    printf("%lld", y);
    
    return 0;
} 

