#include <stdio.h>
#include <math.h>

int gcd(int a, int b){
        int t;
    while (b != 0) {
        t = b;
        b = a % b;
        a = t;
    }
    return a;
}

int main(){
    FILE *in=fopen("fractii.in", "r");
    
int n, count=0, i, j;
    fscanf(in, "%d", &n);
    fclose(in);

     for (i = 1; i <= n; i++) {
        for (j = i; j <= n; j++) {
            if (gcd(i, j) == 1) {
                count++;
            }
        }
    }

    FILE *out=fopen("fractii.out", "w");
 
    fprintf(out, "%d", count );
    fclose(out);
    return 0;
}