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

int cmmdc(int X, int Y){
    int r;
    while (Y != 0){
        r = X % Y;
        X = Y;
        Y = r;
    }
    return X;
}

int numberOfFractions(int n){
    int index1, index2;
    int contor = 0;

    for (index1 = 1; index1 <= n; index1++)
        for (index2 = index1+1; index2 <= n; index2++)
            if (cmmdc(index1, index2) == 1)
                contor++;
    return contor;
}


int main(void){

    FILE *in = freopen("fractii.in", "r", stdin);
    FILE *out = freopen("fractii.out", "w", stdout);

    int n;
    scanf("%d", &n);
    printf("%d", numberOfFractions(n));

    fclose(in);
    fclose(out);
    return 0;
}