#include <stdio.h>

int main() 
{

    long long int x;
    long long int num = 0;
    long long int tmp = 100;
    scanf("%lld", &x);

    while ( tmp <= x){
        num++;
        tmp = (long long int)(0.01 * tmp) + tmp;
        if( tmp >= x){
            printf("%lld", num);
            break;
        }

    }
    return 0;

}

