#include <stdio.h>
#include <stdlib.h>

int main(void)
{
    unsigned long x = 0;            // 目標額
    unsigned long deposit = 100;    // 預金額100円
    double interest = 0.01;         // 利子1%
    int temp = 0;

    scanf("%lu", &x);

    while(1){
        deposit = deposit * (1 + interest);
        temp += 1;
        if (x <= deposit){
            break;
        }
    }

    printf("%d", temp);

    return 0;
}