#include <stdio.h>
#include <string.h>

int knock(int src_num, int max_num) {
    int i = 0;
    for (i = src_num; i > 0; i--) {
        if(i * 2 + (src_num - i) <= max_num) {
            return i + src_num;
        }
    }
    return -1;
}

int main(void) {
    int input_num = 0;
    scanf("%d", &input_num);

    int current_num = 1;
    int itr = 0;
    while(1) {
        if(current_num >= input_num) {
            printf("%d\n", itr);
            break;
        }
        current_num = knock(current_num, input_num);
        itr++;
    }
    return 0;
}